VIGNETTES INVISIBLE LIFE. -'7 VIGNETTES FROM INVISIBLE LIFE. JOHN BADCOCK, F.E.M.S. KEPHIXTKII. WITH A /IfllTlONS, FROM "TIIK ST. JA .I//.X.S (1AZKTTE. LONDON, PARIS $ NEir YORK. 1883. [ALL KIOHTS HKSKHVKD.] PREFACE. THIS is a very pretentious little book. It assumes as a fact that very few even otherwise well-edu- cated people, know anything whatever of the life here treated of ; and consequently pretends to convey that knowledge to them, or at any rate to introduce the subject to their notice, and so perad- venture awaken such an interest in their minds as shall induce further investigation. The microscope reveals a new world of life and beauty. " The invisible appears in sight; " and it may be confidently predicted that at no very dis- tant period no one will be considered educated who does not possess a knowledge of its revelations, and that all such who have the means will become pos- sessed of the instrument. - Neither, considering the present tendency of the makers to produce cheap and popular microscopes, need the expense be a viii I 'HE FACE. hindrance to any steady mechanic or day-labourer that wishes to have one of his own. The difference between the knowledge obtained from books and that gathered from observation, is immense. In the former you are taking it diluted or at second hand, at least. In the lat- ter, you have it direct, with all its inspiration, from the " fountain head " or great source of all knowledge. It is superficial and easily forgotten in the one case ; while in the other it becomes part and parcel of your intellectual nature, which no- thing can destroy. In the one instance, you may become a very " book- worm " and yet know but very little your mind " cribbed, cabined, and confined " with the ideas, prejudices, and systems of other men. In the other, the illimitable expanse of nature opens its glorious vista to your enchanted vision ; your spirit bounds with delight ; you press for- ward ; you drink from the fountain ; your whole being is saturated with divine impressions ; you are grasping the sublimest truths and realising the highest bliss of Avhich our common humanity is PREFACE. ix susceptible. None will ask the now common ques- tion, " Is life worth living ? " who will rise to the realisation of such experience as this. With them the impression will be rather that " Life is all too short " to compass but a small portion of the boundless realms of knowledge ever opening up to them. The desire for Immortality is not only awakened it is intensified by every fresh accession to the store of this divine wealth , and, growing in intimacy, they become one in spirit with the beauty, harmony, unity, order, joy, sorrow, and unspeak- able beneficence of the universal Divinity, who, permeating, pervading, animating, directing, and controlling, is the great eternal " All in all." The great founders of the religions of mankind, and the seers and the moralists, were in their several ways, and according to the means at their disposal, students of Nature. They were, before all things, impressed and inspired by communion with her, and drew thence their loftiest teachings for the guidance of millions. Whatever there is x PREFACE. of good in all the diverse religious systems of antiquity is derived from this source. The truths thus acquired still stand out as gems amidst a mass of rubbish, or as light in darkness, life in death. If in comparative ignorance such results were obtained, what might not be expected and realised with our present means and appliances ? With the accumulations of the past as aids and warnings, how much greater should be our success ! How truer our inferences and sublimer our inspirations ! This is the goal to which humanity is tending ; and to the aiding of this result this little book is offered as one of the smallest contributions by its author. " By swift degrees the lovo of Nature works, And warms the bosom ; till at last, sublim'd To rapture and enthusiastic heat, We feel the present Deity, and iaste The joy of God." CONTENTS. PAGE I. PLANT-ANIMALS 1 Epistylis, Vorticella. Charchesium, Zoothamnium, &c. II. REVOLVING ANIMALS 10 Conochilus volvox. III. THE BRICK-MAKER .18 Melicerta ringens. Melicerta tyro, &c. IV. TUBE-DWELLING ROTIFERS .... 27 lAmnias, Cephalosiph on. (Ecistes, &c. V. CRYSTALLINE VASES AND THEIR INHABITANTS . 36 Floscule. Stephanoceros. VI. REVOLVING PLANTS 48 Volvox globator. 39685 xii CONTENTS. I'AGE VII. LIVING MATTER 57 AmcBba. VIII. ANIMATED TRUMPETS, HATS, AND PURSES . . 64 Stentors. Bursars. IX. HYDRA 73 X. WATER-BEARS AND ROTIFERS . . 84 XI. COMPOSITE ANIMALS 94 Plumatella, &c. XII. THE SUN ANIMALCULE 104 Actinophrys sol, &c. XIII. STAR-LIKE ANIMALS 113 Acinetons. XIV. SOCIAL il CROWNED HEADS " 123 Meyalotrocha, Lacinularia. XV. A SUBAQUEOUS CITY 139 Sponges. XVI. NATURE'S JEWELS 157 Diatom*. VIGNETTES FROM INVISIBLE LIFE. I. PLANT ANIMALS. f( Joy you in fairies aud in elves ? We are of that sort ourselves." CAMPION. " Full Nature swarins with life ; one wondrous whole Of animals or atoms organised." THOMSON. WHAT we have sketched on the next page resembles a tree ; but when the drawing is examined certain peculiarities of an exceptional character present themselves. There are the trunk and branches and flowers, but no leaves. But many trees develop the flower first. And then in our sketch there is no sign of leafage ; neither are there any roots. Again, the flowers themselves seem to be fringed with hair. Obviously, there is something new and strange about this apparent tree ; and it is indeed 2 VIGNETTES FROM INVISIBLE LIFE. remarkable, and hardly known to any but scientific men. More than 200 years have passed since the subject of our sketch was first discovered, yet very few people have heard anything about it, and fewer have ever seen it. The original observers of it and FIG. 1. Epistylis grandis. its fellows, at first much puzzled, named them bell- flower animals ; and in truth this sketch represents an animal-tree. It seems rather an impossible sort of name. The words " animal " and " vegetable " indicate the two great natural kingdoms into which all life on this globe is divided. Yet here is a name combining the two ideas in one object ; but then that is what the object itself does. PLANT ANIMALS. 3 Let us describe this " animal -tree." In the particular species we have figured the trunk and branches are rigid, while the flowers are active with all the phenomena of animal life. It lives in water, and in order to get food sets up a whirl or vortex by means of its fringes of cilia. Each flower is a living and active being that selects its own food ; and in due time, leaving the colony, wanders off into the world finally settling down and founding a family of its own. First it will develop a stalk, and fix it to some steady object. Then after a time its activity becomes less ; it seems to sleep, and gradually to contract a little longitudinally. This process continues until it has actually accomplished a wonderful feat : it has produced its double a companion in all respects soon to be its equal, and to assist in the great work of founding a colony in a tree form, complete with trunk and branches like the one from which it originally migrated. Such in brief outline is one of its many transformations so wonderful that the German naturalist Ehrenberg compares them to that of an old man going through a process by which he should regain all his youth and vigour. B 2 4 VIGNETTES FROM INVISIBLE LIFE. We have seen that the active life is in the flower : the trunk and branches stand in the same relation to it as the shell does to the snail. You may often observe the rigid and flowerless trunk and branches standing bare all the flowers gone, and life extinct. Some of this class of creatures develop flexible trunks and branches capable of rapid and beautiful changes ever and anon changing from a wide- spreading forest-like tree to a small and compact mass ; others, again, develop only spiral stems, which they attach to the leaves or stalks of weeds. In the composition of all, however, there is more of the animal than of the vegetable. By this time, of course, the reader will have gathered that the thing here described is of micro- scopic dimensions ; and in fact its natural size (as will be seen by reference to the little figure to the left in our engraving) is no bigger than a pin's head, and presents no sign of organic structure to the unassisted vision. It seems to be simply a bit of dirty matter. Sometimes these creatures collect in such vast numbers as to form large masses of what looks like slime or filth, adhering to water- plants or pieces of decaying branches of trees, or PLANT ANIMALS. along the banks of our canals and ponds. That things are not always what they seem, is here very forcibly illustrated. You take up a portion of this apparently dirty slimy mucous matter say on the FIG. 2. Charchesimn polypinum. point of your walking-stick and your first impulse is to throw it away in disgust. Put it again into the water, and it is seen to spread itself out in a less repulsive appearance. Take up a small portion again, put it in a small glass bottle of water, and peer at it through a pocket lens ; it 6 VIGNETTES FROM INVISIBLE LIFE. begins to look attractive. You carry it home, and, placing a small bit with a drop of water in a glass trough or on a glass slide under a good microscope and with proper illumination, you behold a most charming picture. The repulsive bit of slime is transformed into trees and flowers, and all in active and beautiful motion. Here may be seen one with wide-spreading branches, w r ith flowers and fruit, and, to all appearance, with birds sitting on its branches. Seeing as much as this, you would hardly be surprised if the birds opened their mouths to sing, and the fruit (like large oranges) dropped in its ripeness. What you do see is almost as strange, for the tree looks alarmed. You have, perhaps, touched the table or the microscope, and so produced a slight vibration which has thus reached the highly sensitive group before you ; and down it sweeps, branches, flowers, fruit, birds, trunk, and all, in tiny contraction. You can only see now, even with good magnification, a very small dot of matter ; but with returning quiet a slight movement is visible. It increases ; the tree spreads out, and is all there again : nothing has been injured. This process is constantly repeated, PLANT ANIMALS. 1 and is a very charming thing to see. The birds, of course, are an illusion ; but on one of the species ZootJtamnium arbuscula there is really fruit. It has all the appearance of fruit as seen on an ordinary tree, and it answers the same purpose as the vegetable fruit of the apple or orange. It is seed, from which new individuals and colonies are to be developed. As for the birds the writer has seen small and very pretty rotifers on the branches of this Zoothamnium looking so much like birds on a forest-tree that he could not help the comparison. Not that they are struc- turally like any known species of birds ; but here one is, so to speak, in fairy-land. Before us a tree, contracting and expanding itself at pleasure ; having flowers vibrating with active life the corollas mounted with rotating discs, and visibly feeding on surrounding matter, with intelligent selection of the food required ; and, perched on its branches, small and beautiful creatures that kept their places with the alternate contractions and expansions of the trunk and branches. Under these circumstances, there was nothing surprising in observing that those ^" birds " were crowned 8 VIGNETTES FROM INVISIBLE LIFE. with (apparently) revolving wheels instead of feathered heads with beaks, and clung to the branches with a fork-like foot, instead of having legs and claws. It seems difficult to avoid using the words " tree " and " flower," &c., in connection with objects, though animal, which by their appearance naturally suggest them ; and one is thus led to ask, whether there really is that great division in nature denominated by the words " animal " and " vegetable " ? At any rate, whatever may be the case in the higher class of beings, this division fails us in the world of microscopic life, for not only by their forms, but more by their qualities do they deny us that division. They possess the attributes and faculties belonging to both the great kingdoms of Nature animal and vegetable. Moreover, they fluctuate between the two, being at one time more animal and anon more vegetable, while at the same time combining the attributes of both in an ever-varying degree. Thus a new kingdom has been suggested, to which the term Protista is given. It must not, however, be supposed that these remarks apply PLANT ANIMALS. 9 in all their fulness to the particular family of crea- tures described in this chapter. The microscope alone reveals this new kingdom of nature, and we have here selected only one type of the strange life contained in it. II. KEVOLVING ANIMALS. " Thou man, who art the universe in little, cease for a moment from thy absorption in loss and gain : take one draught at the hand of him who presses creation's cup to thy lips, and so free thyself from the cares of this world and those about another." (PERSIA) KEIJAM. JUST within the border of Epping Forest, in the neighbourhood of Walthamstow, is a number of ponds and ditches in the fate of which some few naturalists are at the present time * nervously in- terested. It is reported that the City of London Corporation intend to drain and otherwise im- prove this neighbourhood; and as this may mean the obliteration of these precious ponds, the lovers of nature, or the special kind of that nature in this special district, are alarmed, and would fain draw off the drainage operations to other localities. As the * The reader must remember that this was written in April, 1882, and was then also published in the St. James's Gazette. ED. EEVOLVING ANIMALS. 11 ponds in question are not very pretty objects, the reason for this anxiety 011 the part of naturalists must he somewhat puzzling to the general public. I propose to enlighten them on this point by de- scribing some of the rare forms of life that would thus be destroyed. The Conochilus volvooc, of which we print a FIG. 3. Conochilus volvox. sketch, is only found in a very few favoured places, and that of the ponds referred to above is one of them. The winter is the best season for getting the creatures in their prime. I have always found them in best condition and in greatest abundance when the ice had to be broken to fish them up. The usual method for collecting these and similar 12 VIGNETTES FROM INVISIBLE LIFE. creatures is with a bottle screwed on to a ring at the end of a stick (collecting- sticks, made for the purpose, may he hought), and dipping here and there until you find what you seek. Having drawn up your bottle of water, you apply a pocket lens to the contents ; and if you have caught the objects of your desire, you will see a number of small white rolling bodies, the Conochilus volvox. Not that all small white rolling objects are Conochilus. These small white revolving objects, when placed under the microscope, appear marvellous and beautiful. We are all led to speculate some- times'upon the forms that life may assume in other worlds than ours. For those of us who are familiar with the use of the microscope these speculations and fancies are much widened : and I for one have come to the conclusion that nothing that could be found in any other world is likely to exceed in strangeness or beauty the actual forms of life which exist in countless millions in our own. Of these one of the most remarkable is the white rolling globe that may be gathered from the pond at Walthamstow. First, bear in mind the size of the globe or the REVOLVING ANIMALS. 13 white speck I speak of. A dot of the pen thus * will represent its natural size ; and yet this dot is com- posed of about forty organised and complex animals, each one having a distinct individuality. The individuals of which this globe is composed are, as I have already remarked, of a somewhat complex organisation. There is the head with its crown of cilia, which by its vibrating motion resembles a wheel rotating on a pivot. This motion is common to most of this class of animals, and originated the name under which they are classified namely, Botatoria or, commonly, wheel-bearing animalcules. The rotatory motion is, of course, an optical illusion. It is like that of a field of corn set in motion by the wind; and if you imagine the wave -like motion thus produced to move in a circle, you will have before your mental vision the same appearance on a large scale as is produced by the Rotifers. By this motion a little vortex is created in the water around their heads and mouths, and down this tiny whirlpool their food is carried. They have each two eyes ; manducatory, alimentary, and reproduc- tive functions ; also a suctorial foot by which they attach themselves to a common centre. This attach- 14 VIGNETTES FROM INVISIBLE LIFE. ment is very remarkable. No one has as yet observed trie actual formation of the colony in this form from the commencement ; but I have frequently seen the colony divide, and this is a most singular process. You have a fine group of, say, forty individuals under observation in a compressorium ; and while you watch, separation takes place not into indi- viduals, but into groups ; so that, instead of one globe of forty, you have two of twenty. No injury is done. It is as if an understanding had been arrived at that one half should go to the right and the other to the left ; and the thing is done in an instant. There are eggs, and young ones are con- stantly being produced; so that the number of individuals forming any one group is not the same for any length of time : the number varying from ten to forty, and all attached to a common centre by their foot-like tail, which is furnished with a suctorial organ for the purpose. To keep the colony together, each member has to contribute something of vital importance. This is of a mucous or gelatinous nature, rather more dense at the centre than at the extremities, and it sur- rounds and keeps all together. This bond of union REVOLVING ANIMALS. 15 is very transparent; so that while it serves as a common shelter within which each individual can retreat at will at the approach of danger, it does not obstruct the view of the beholder. When kept for any time beyond an hour or two under observa- tion in a contracted space and in a warm atmosphere, this gelatinous envelope becomes soft; and the individuals forming the colony, no longer held closely and firmly together, slip out one by one, stray about helplessly, and soon perish. This probably is the reason why these creatures flourish best in cold weather. In some instances the mucous investment of the Conochilus is green, or partially so, and is probably caused by the nature of the food on which they have been feeding ; and this beautiful gauzy transparent green membrane- ous matter enveloping the white crystalline ro- tating colony, adds greatly to its beauty. Before this strange little colony breaks up, let us note it more particularly. Remark that each member is furnished with an apparently re- volving or rotating wheel-like head in fact, a wreath of cilia which, lashing the water from nearly all points at once, produces a whirl or vortex. The 16 VIGNETTES FROM INVISIBLE LIFE. whole group doing this together, and almost in- cessantly, causes it to roll over and over; so pro- ducing the appearance of a sphere of transparent and beautiful creatures, each one revolving on its own account, and the whole revolving together in perfect harmony. There is but one known species of these creatures, and they are not found every- where. But they are found in abundance, tens of thousands of them together sometimes, in these Walthamstow ponds. Can we then wonder that there should be some anxiety lest one of their well- known and easily accessible habitats should be destroyed ! The microscopist dealing with things invisible to ordinary vision, and consequently with forms of matter with which the general public are unac- quainted, labours under some disadvantage, appear- ing to attach too much importance to such minute objects ; but a little consideration will surely dispel all such notions. The investigations of science within the last few years have made it apparent that our own welfare physical, mental, and com- mercial depends considerably on the compara- tively small and invisible forms of life with which REVOLVING ANIMALS. 17 our lives are environed on this earth ; while the great globe itself owes no small portion of its form, beauty, and fertility to the united labours of the countless millions of its infinitesimal inhabitants. III. THE BEICK-MAKEK. " Though lowly here our lot may be, High work have we to do." GASKILL. " There is no great and no small To the soul that maketh all." EMEESON. THE Melicerta ringens is an animal so small that, although it lives in a brick-built house or castle of great beauty and strength, one might swallow a score of them in a mouthful of water, houses and animals altogether, without noticing them; and therefore to ascribe intelligence to an animal so small seems at first sight rather preposterous. Small and great, however, are only relative terms ; and in the region of microscopic life, this creature is rather a large one as compared with thousands of others as large, indeed, as an elephant is to a mouse in the visible creation. Thus regarded, the objection as to size vanishes. The vignette represents a group of these very THE BEIOK-MAKEB. 19 interesting animals in tlieir dwellings ; or, rather, they are partially showing themselves from the one opening on the top. They are rarely found in a social condition as here shown, generally preferring a detached residence. In this instance quite a FIG. 4. A Group of Molicertans. group have collected, and built their habitations around and on the parental structure. The young are developed from eggs, which are laid and hatched within the tower-like house. Owing to the peculiar structure of its inhabitant, great care is required in this process. The egg is shot forth near the top of the tower and caught within it, falling gently c 2 20 VIKNETTES FROM INVISIBLE LIFE. alongside the animal to the bottom, where it is hatched, and the young protected until they quit the parental abode, to which they never return. A young Melicertan is a very different creature from its parent, having two eyes, and swimming rapidly from place to place. This is the period of youth ; free and easy, it travels over its little world. Soon, however, it gets tired of this roving life, and selects some congenial spot on which to build a house, and, having attached itself or literally put its foot down never removes. It is generally some filament of algae or other water- plant to which this attachment is made ; but in the instance before us, as we have seen, the parental dwelling is chosen. The eyes now disappear from ordinary view, being changed from the prominent eye- spot character hitherto presented into ex- quisitely fine crystalline ruby-like points. In this condition, and being, moreover, liable to be en- folded in the large trochal organ which is now developed, they are not easily or often seen, and the general inference is that they have disappeared altogether. This, however, is a mistake, as I have often THE BRICK-MAKER. 21 demonstrated their presence. Moreover, the idea suggested by their presumed disappearance, that because the creature no longer leads a rambling life, that therefore it no longer requires organs of vision, is out of harmony with all natural analogy, and especially so with the animal before us. Our further observations place it among those beings on whom nature has bestowed complexity of structure, and relatively high capacities for both use and enjoyment. And first, let us remember, our tiny acquaintance is naked and homeless. Nature, however, is kind, and has furnished it with a ready-made brick- making machine ; which, being part of its own organisation, is ready for immediate use and is not likely to get out of order. Perched on the leaf of a plant, the machinery is set in motion : a trans- parent flower-like crown, having four lobes, is gradually expanded. This is fringed with a double row of cilia, which produces a motion of exquisite beauty. It is of a rotary character ; and so, by producing a corresponding motion in the surrounding water, any inorganic matter therein floating is drawn into the vortex, is caught up by the 22 VIGNETTES FROM INVISIBLE LIFE. expanded leaflets, and carried round between the double row of cilia towards the mouth. Here an im- portant operation has to be performed. The mate- rial collected is not all fit or required for food, and consequently a sorting or selection is made before it is admitted : some is sent down to the gizzard, there to be more finely triturated and passed on as food ; other is taken into the pug-mill, as the brick-making machine is often called ; and the remainder rejected as worthless. There is no stoppage of any one operation for the performance of another : collecting, sorting, grinding, and brick -making are all going on simultaneously. You have before you a beau- tiful piece of machinery, and hardly know which part of it to admire the most. Let us for a few minutes watch the brick-making operation. We see a few grains of matter spinning round, which every moment is growing denser, acquiring consis- tency and a rounded or conical form. " In three minutes it is finished and deposited on the outside, where a film of gelatinous matter is already waiting to receive it. Thus the first brick is formed. Others follow in due course ; and soon a ring of them is formed round the middle of the animal : THE BRICK-MAKER. 23 pellet by pellet and ring on ring is added, and gently and gradually pushed down until the base- ment is reached to which the architect is fixed. To this basement the building is firmly cemented ; and the house may now be said to be constructed, and only requires additional rings of bricks in pro- portion as its occupant grows and requires more room for shelter and repose. Pondering over the selective character of the " sorting " operation above referred to, one feels that it can be due only to intelligent perception of the difference between one kind of matter and another ; and this conviction is confirmed by the following observation. A loose mass of effete matter is thrown forth with more than ordinary force, and in the usual habitat of the creature in a pond would speedily be carried away. But here, in the contracted space of a small glass trough, it is repeatedly brought back within the little whirlpool created by the ciliary action of the trochal disc, and we expect every moment to see it carried down the vortex to the stomach along with its food. But not so, it is not even admitted to the sorting apparatus before described, but is at once and 24 VIGNETTES FROM INVISIBLE LIFE. peremptorily rejected, and thrust back again and again with increasing force, as often as it comes within the ciliary current. Now in reference to much of the motion pre- viously observed, it may be conjectured to be inde- pendent of the will, but in this instance exceptional conditions are imposed to which the creature re- sponds by as intelligent action as it is possible to conceive. Nor, considering the complexity of its organisation and its relative rank in the scale of invisible life, is there so much improbability in the fact of its intelligence as at first might appear. But it is not intelligence alone, or even principally, which enchains the attention ; this may be equally shared by other minute beings : it is the extraordinary beauty and mechanical con- trivances which renders it so general a favourite. Moreover, it lives and thrives well in confinement, and has no objection to some interesting experi- ments making and building with coloured bricks, for example, if we give it the colouring matter. Let us take another look before leaving. Touch the table or the microscope a little roughly, and danger is apprehended by the Melicertan : quick as THE BRICK-MAKER. 25 thought it retires within its stronghold. But if now we wait and watch we shall perceive two fine projecting points, tipped with fine setae or hristles : these are feelers or antennae, and give the required information as to danger. When satisfied as to its security, it prepares to come out and resume work : there is a gentle trembling and quivering around the bulwarks ; the head is thrust out and again withdrawn, as if in doubt of safety. Finally assured, the flower-like trochal disc is gently expanded and unfolded. There is another Melicertan which merits mention, although it has been named " Tyro," by comparison with its more exalted neighbour. The reason of this designation being that while the creature is furnished with the ciliated cup, i.e., pug-mill or brick-making machine, it yet does not make any bricks at all. The organisation and material are both supplied, yet no result appears. This is not the usual method of nature's working in the ascending or progressive scale of development, and the disuse of this organ must be rather regarded either as indicating reversion or retrogression, than an attempt to reach the level of M. ringens, which '26 VIGNETTES FROM INVISIBLE LIFK. the word " Tyro " suggests ; as its disuse may be ascribed to an advance in organisation in another direction, or an environment which rendered it no longer necessary ; or even it may be the result of accident in some remote ancestor, who neverthe- less managed to live and perpetuate the injury to its descendants. Instead of making bricks and building a home, M. tyro secretes a glutinous covering, in which it moves and has its being. This is of rather a loose texture, and may be regarded as approaching the Limnias, described in our next, or to that of the Floscules in No. V. To return, " Mclicerta tyro is a Melicertan with a gelatinous sheath very like that which invests the Floscules, and yet with a distinct character of its own." Its trochal disc is four-lobed like that of M. ring ens, but with more of a "butterfly" character when expanded, and having two long antennae. Moreover, the eyes even in the adult form are more readily seen than in M. ringens, or the Floscules. All things considered, it does not seem to be undergoing a process of de- terioration, notwithstanding the loss of its brick- making faculties. IV. TUBE-DWELLING KOTIFEKS. "At the foundation of all organisation there is an original intrinsic kinship." GOETHE. " In truth, nature has no such fancies as those man is ever ready to credit her with. She has but one law endless variety ; and her varieties blend into one another by such fine gradations that no natural system of classification can be other than unsatisfactory, doomed to be destroyed and re-cast by each succeeding generation of naturalists." C. T. HUDSON. ALL careful observers are familiar with the grada- tions in the scale of life : every class, whether animal or vegetable, presenting such differences in organisation and habit as indicate a gradual progression towards perfection, with occasional re- lapses, or retrogression. In Melicerta ringem (described in No. III.) we have the highest this form has reached ; and between that and the lowest, are several grades approaching more or less closely to perfection. There is M. pilula, for example, which is at once observed to be lower in the scale by the striking 28 VIGNETTES FROM INVISIBLE LIFE. contrast between its dwelling and that of its near relation M. ring ens. Without going into details of structure, one observes that it has only a two-lobed trochal disc, or crown (which, however, is very beautiful), and that, although furnished with a cup- FIG. 5. Limnias ceratophylli. like organ, or pug-mill, yet it does not make bricks like M. ring em : this cup-organ only secreting a gelatinous fluid, with which the creature invests itself, and on which it drops or throws pellets of mud or rather excrement. These, sticking to the viscid secretion, gradually, and without any sym- metry, form a covering or refuge. So that while the TUBE -DWELLING ROTIFERS. 29 former gets a mansion built with mathematical precision, on a symmetrical plan, from materials carefully selected, the latter gets only a mud -hovel formed, or thrown loosely together. While the one structure is strong and enduring, forming a monument of stability even when uninhabited, the other is always falling " about the ears," so to speak, of its possessor. Between these two extremes are several others, of varying perfection in structure and capacity. Our illustration shows a group of Limnias ceratophylli, the "two-lipped tube-wheel of the Hornwort." The Ceratophyllum demersum or Horn- wort, as it is commonly called is its favourite re- sort, and has originated the specific name of the creature ; but it is by no means specific of its habitat, for the animal will attach itself to almost any water-plant, and is found in great abundance in the canals about London. Somewhat resembling the Melicertans, Limnias yet presents many differences, the most noticeable being the form of the flower-like wheel and the structure of the tube-like dwelling. But while M. ringens builds with bricks, and M. pilula with pills 30 VIGNETTES FUOM INVISIBLE LIFE. or pellets, Limnias constructs its house with thick gelatine of rather a horny consistency ; and being at first soft, it forms good material for the attach- ment of foreign bodies and the young ones who may chance to light upon it ; for these, like the young Melicertans, are at first free-swimming, and have two eyes, which they appear to have lost on arriving at maturity and a fixed abode. The wheel-like organ consists of two nearly circular lobes, or lips, fringed with cilia, showing all the appearance of rotation as each wave of cilia follows its fellow round the course, thus producing a picture of great beauty to the beholder. This ciliary motion, or some modification of it, is almost universal in all microscopic animals as it is also in some of the tissues of the higher forms of life and is the method by which nourishment is col- lected, and in some cases locomotion achieved. We see then, the food collected by the ciliated flower- like lips, and passing between them, down the buccal funnel, through the aesophagus, or gullet, to the manducatory bulb, or mastax ; which latter consists of jaws furnished with strong teeth, work- ing on each other, tearing and grinding the smaller TUBE-DWELLING ROTIFERS. 3L animals and other organic materials collected from tlie surrounding water. It seems almost like drawing on the imagination to speak of jaws and strong teeth, &c., &c., in creatures so small as to be only just discernible with the aid of a pocket-lens. Yet it is no fancy sketch; nay, more, the organs of which we speak are not only clearly distinguishable with the aid of the microscope; but some of them, such as the mastax of M. ringens, with its jaws and teeth, have been dissected out and mounted on glass as separate objects of interest. This mastax is a prominent feature in all the Rotifera, and at once attracts the observer's atten- tion. It consists of three well -developed lobes, or masses of muscle, two of which, with the teeth, are seen to be working against each other, grinding down the food on to the third, which forms a sort of table. The food thus finely triturated is now passed on to the digesting stomach or alimentary canal, which is divided into several compartments, each furnished with its appropriate secretions for converting the food into the tissues of the animal body, &c. In fact, all, or nearly all, the organs 32 VIGNETTES FROM INVISIBLE LIFE. of the higher class of animals are here found in miniature, so small and delicate, and yet so effective as to excite our highest admiration and wonder. Are not the facts of nature stranger than any imaginable fiction ? To return to the illustration on page 28, it is seen that a number of individuals are grouped together, the central one being probably the founder of the colony. Sometimes twenty individuals will thus attach themselves ; but their doing so is not habitual : it is simply a matter of choice or accident. As before observed, when young they swim about in freedom : but not for long; as a firm and permanent support becomes necessary. Looked at in a glass trough under the microscope, they are seen to try several positions sometimes the glass sides of the trough before finally deciding where to settle. When, how- ever, this is done, they remain ; and developing, as we have seen, the prime materials for a habitation from their own bodies, work out their little destiny. The tube or dwelling thus formed is about one- fiftieth of an inch in length, at first semi-trans- parent, but becoming brown with age and the ad- TUBE-DWELLING ROTIFERS. 33 hesioii thereto of foreign matter. When completed it is cemented to a firm support, and is no part or attachment of the bod^ of its maker. This grouping or association into colonies, both of these and other organisms, is very suggestive. The tendency is more or less developed in propor- tion to the strength or weakness of the individual, and the peculiarities of its environment. Some forms of life there are of a much humbler character than those now under consideration, which yet are solitary in their habits ; it will, however, be found, on close examination, that they are furnished with some subtle means, both of offence and defence, which is often more than a match for those of much higher organisation in the struggle for ex- istence. Confining our attention for the present to the Limnias and its relatives, we find it very interesting to observe the various methods adopted in these associations. Thus the Conochilus shelters all its members in one common protecting substance which envelopes the whole family circle. The Limnias, on the other hand, preserves its individuality, while yet combining with its neighbours in grouping D 34 VIGNETTES FROM INVISIBLE LIFE. their dwellings together, and so offers greater resist- ance to any sharp-eyed and rapacious strangers of which there are many who may be disposed to gobble them up. The former is the " family," the latter the "social" life. Closely allied to Limnias are (Ecistes, Ceplia- hmpJio/i, and others all tube dwellers and bearing a strong family likeness to each other. The differ- ence between Lintmas and (Eciste* consists princi- pally in the character of the rotary organ, which in the former is ^/-lobed, and single in the latter; while in Cephalosiphon there is an additional attraction in a curious syphon-like projection, the use of which seems to correspond to the antenna? of insects as a projecting feeler after information for the benefit of its proprietor. There is yet another tube-dweller which must not escape our notice. It is described in the "II. M. &. Journal" for December, 1878, as a new form, and obtained the name (Ecistes iimbellu, from the peculiar umbrella-like form and structure of its circular disc or head. There are the ribs and covering, and when fully expanded or partially folded up, the resemblance, as far as the upper TUBE-DWELLING ROTIFERS. 35 part is concerned, is very striking. Of course the handle or what is here the body of this beautiful creature is very different to that of an umbrella, and is furnished with all the usual alimentary and other organs essential to its well-being. V. CRYSTALLINE VASES AND THEIR INHABITANTS. "If we consider plauts aiid animals ill their most imperfect con. dition, they can scarcely be distinguished. But this much AVI- can say, that the creatures which by degrees emerge as plants and animals out of a common ph ase arrive at perfection in two opposite directions ; the plant in its highest glory reaches the tree ; the animal, in man." GOETHE. WHY or how it has come to pass that Nature puts on such a variety of forms is rather a puzzling question, especially so to those who insist on separate creations for every one of them. If, how- ever, instead of starting in our investigations with a preconceived theory, we simply examine and note the facts of natural history, we are charmed witli this infinite variety, and are under no temptation to twist and distort what we see to make it fit into any theory. The great drawback is the almost bewildering classifications and terrible names which, CRYSTALLINE VASES AND THEIR INHABITANTS. 37 under the specious show of great learning, are now presented to us. These things are at last in such a muddle that they are more difficult to master than the objects they are designed to teach ; and, indeed, if one would really learn as much as Fio. 6. Floscularin campamtlata. possible of the operations of Nature, he must leave those devices of man to come in after, and not at the commencement of, his studies. He must go to Dame Nature's own school, and little by little learn all about her, even as a child learns to walk and talk. Pursuing this method, we eventually find that organic life on this earth is not split up into sharp and well-defined classes as at first sight might be 33 VIGNETTES FROM INVISIBLE LIFE. supposed. Underneath the appearances is seen the one continuous stream of life, modified by its en- vironment, and branching off in various courses, more or less complex according to the obstacles to be overcome, but always preserving its own essen- tial character. This being so, while similarities must appear in the several branches, one is not sur- prised at not finding any sharp dividing lines, and is not disposed to wrangle over classifications which do not exist in nature. The substance or the matter of life is found to be plastic, and hence variable ; intelligent, and therefore adapting itself to its environment ; is progressive ever aiming at the highest possibilities of existence. All its many phases are seen to be the natural outcome of these its main characteristics, from the simple bit of plastic matter we name the Amoeba, up to man himself. To come to the main object of this paper. The almost invisible forms of life are operated on by the same causes as the larger and more complex organisms ; and the reason why a Melicertan builds a house is the same as that which develops a thorny covering for the hedgehog. Self-preservation is tl.e first object to be secured ; and the varying devices CRYSTALLINE VASES AND THEIR INHABITANTS. 39 resorted to for accomplishing this end are dictated by surrounding circumstances, though we cannot always trace them. The Floscularia comprise several varieties or species ; but this one, a group of which are here sketched, is the Floscularia campanulata the flat- leaved Moscule or flower. Actual flowers, being visible, got their names before those little creatures which so much resemble them, and which are thus in so many instances named after them. This one has five petals or lobes constituting its head. On the angle of each petal is a tuft of seta3, or bristles, very long and fine, and which when expanded fall in a "graceful shower" around the body of the animal. Although classed among the Eotifera, it yet has no rotating organisation ; -but a faint line of cilia inside the lobes and along the mouth produce a current in the surrounding water towards the opening, carrying with it the food required. This food is of both animal and vegetable nature, mostly small infusoria and motile plants, which in its transparent body gives it at times the appearance of a crystal goblet full of jewels. Of the general varieties of Floscules, F, ornata is perhaps the 40 VIGNETTES FROM INVISIBLE LIFE. most beautiful. Its crystalline dwelling is finer and its movements more graceful than the others. Why F. campanulata is here sketched in preference is because of the exceptional character of the group. They are solitary in their habits as a rule ; but here seven individuals (only six are drawn) were found attached to the stem of a water-plant so gracefully arranged, forming a most delightful picture. Instances of this character are often found in nature ; where separate individuals, as if following the law which by its predominance has made them individually beautiful, combine to form another beautiful object, just as a little child may collect a bunch of wild flowers and arrange them in a pleasing nosegay, or join hand-in-hand with companions in a dance on the village green. These natural groupings of beauty are very instructive, as showing the almost universal tendency in this beneficent direction of all animate and inanimate things alike. They form the pictures which the artist loves, and which he will travel miles to see and immortalise on his canvas, and the micro - scopist sit long into the " stilly night " beholding with wondering and enchanted vision. CRYSTALLINE VASES AND THEIE INHABITANTS. 41 The Floscule is developed from an egg, and when young, like some others we have described, has two red eyes and is free to roam about as it likes."*" After a time it attaches itself generally to some plant and develops its habitation. This consists of a gelatinous secretion, very transparent, and is formed into a cylinder or tube around its body, in which it lives. One is not impressed with a sense of its security, as is the case with M. ringens, so much as with its beauty. Its dwel- ling being transparent, all its charms are seen, and the wonder is that it escapes its enemies. One arrangement, however, is very curious, as being apparently designed for protection. When the Floscule retires within the vase, the flower-like crown with the five or six bunches of long bristles is folded over transversely ; but the bristles, being so long and thus drawn together, form a projecting broom-like appendage, rather formidable to any would-be intruder. Now, the vase being so trans- parent, this arrangement, if intended for protection, * The eyes, both in Floscule and Stephanoceros, are generally supposed to exist only in the young. This is an error, for I have repeatedly demonstrated by experiment their existence in the adult forms. 42 VIGNETTES FROM INVISIBLE LIFE. is somewhat like that of the ostrich hiding its head in the sand while its body is uncovered and visible. At any rate, it has managed tolive and thrive, though not so abundant as some of its better-defended relatives. Not much has been said as to the beauty of this creature : in words it is difficult to describe this striking feature. Imagine if you will, a lovely flower-like animal within a fine crystalline goblet ; it is folded up for the moment, but its life is too short for long repose, and soon it proceeds to resume its normal state. The petals open, expand, and the finely spun glass-like seta>, finer than the finest hair you ever saw, are thrown forth in flowing flossy masses, glistening in the light with opaline tints, and, spreading out in all directions beyond our utmost gaze, all in wavy lines around the body of its possessor. Such is the beautiful Floscule. But the crown of all the Floscularia, the one that stands alone in majesty of form, is the Stepha- noceros, a sketch of which we print. We have no varieties here, at least none sufficient to constitute another species ; and this fact harmonizes well with its unique character and position as the " head of the family " of the Floscularia. CRYSTALLINE VASES AND THEIR INHABITANTS. 43 All through nature one finds examples of this kind, where one branch or rivulet of the great stream of life culminates at a point of perfection beyond which it cannot go : such is the StcpJtanoceros eich- liornii. We take this creature out of its native FIG. 7. Xttphaitoeeros. ditch or pond, where it is found attached to a branch of a water-plant say, on one of the spiked leaves of the hornwort (from which it depends in graceful beauty) and placing it in a small glass trough under the microscope, with a paraboloid or dark-ground illumination, proceed to examine it in detail. If we have a fine specimen it is im- possible not to stop to admire the elegance and 44 VIGNETTES FROM INVISIBLE LIFE. beauty of the creature under our gaze. We may have seen it hundreds of times before, but its attractions never pall. It stands up so erect in its crystalline tower, with its five arms either expanded or folded up in an undeniable kind of majestic elegance. Along the arms are seen numbers of verticils of long and vibrating cilia. Ever and anon a nervous thrill seems to pass along these arms, and the cilia flash out as if charged with an electric current; and presently a small animal, that has for some time been hovering about the Stephano- ceros, descends between its arms and through the wide gullet to its final destiny as food. Concen- trating our attention, we observe what seems an egg within the transparent body of the Stephanoceros ; and, increasing the magnifying power, we can u<>\\ distinguish the small embryo folded up, and its two bright ruby eyes shining points of the finest imaginable character. Now the egg is developed or laid, and remains close up to the body of the parent within the dwelling. Here the very delicate incipient life is securely protected and provided for, and we sit hour by hour to watch the intensely interesting operation of its unfolding. The egg CRYSTALLINE VASES AND THEIR INHABITANTS. 45 does not burst ; the little life within does not break its way out. It is literally an unfolding. It is as a flower unfolds : one by one, its several parts come into view, spread out and take up their functions. Now the cilia move, the creature rolls over, its eyes brighten, it elongates, its head appears crowned with cilia, it straightens out its entire body. The Steph- anoceros is bom, or hatched. What before appeared as the egg-covering is now seen to be the external skin of the animal, within which its embryonic life lay folded up, and in which it is now developed and protected. The exquisitely delicate organism thus developed is still further protected and pro- vided for, until strong enough to care for itself, by the casing in which it now finds itself. This dwell- ing is of transparent jelly, secreted and formed in ring-like folds. When young and in good condition it is more transparent than the finest glass ; gradu- ally it hardens, and is strengthened by those folds which act as stays and foundations for the super- structure as tier after tier is formed. Sometimes the base is extraordinarily strong ; and the whole structure resembles a fine crystal vase, the upper portion being transparent and the lower slightly 46 VIGNETTES FROM INVISIBLE LIFE. opaque and of a more solid and substantial character. It lias been a subject of much dispute whether this tower or case is solid or cylindrical. The truth is that when young it is perfectly cylindrical, with those curved indentations or folds as stays or sup- ports ; and it may remain so under favourable con- ditions for a long time. However, as often as off- spring are produced, so often is there an extra secre- tion of jelly ; and this sometimes fills up the tube so much as to leave only room enough for the animal to move up and down, and the young have to eat their way riglit through it to get out. These re- marks lead us back to the young and but just newly-hatched Stephanoceros. Finding itself sur- rounded by this cylindrical structure, it exerts itself to get out; and, gradually making its way up- wards, swims gently out near the top, where the gelatinous folds are so very thin Mid flexible that no rupture appears to have been made by its exit. No one would recognize this now roving little creature as a Stephanoceros who had not seen it hatched or known it previously ; and it passes through another stage before finally appearing in CRYSTALLINE VASES AND THEIR INHABITANTS. 17 its perfected form. When young and free there is no sign of those five long and beautiful arms, or lobes, which are the chief beauty and characteristic- feature of its mature condition. It has simply a tuft of bristles on its head, two ruby eyes, and a vermiform body ; and in this form it passes the time of youth. Xow it is weary ; life seems ebbing away ; and so, resting on any support in its wav, it appears to fall into a state of coma, or death, like repose, during which the wonders of its perfect nature are being matured, and from which this minute organism emerges to vigorous life. VI. KEVOLVING PLANTS. " The rounded world is fair to see, Nine times folded in mystery ; Though baffled ears cannot impart The secret of its labouring heart, Throb thine with Nature's throbbing brea And all is clear from east to west ; Spirit that lurks each form within Beckons to spirit of its kin ; Self -kin died every atom glows And hints the future which it shows.'' EMERSON. THE Voluoiv glolator here sketched is a very small and beautiful plant. To those unacquainted with the revelations of the microscope, this statement will appear rather startling, so different is this organism from what are usually known as plants. The fact is that we are here again on the border-land or de- bateable ground between vegetable and animal life ; and although the botanists have established their claim to the Fblvocine&, there being more of the vegetable than of the animal in them, yet the posi- REVOLVING PLANTS. 49 tion in classification of all such beings, whether partaking more of the characteristics of one king- dom of nature than of the other, is not considered quite satisfactory ; and some eminent naturalists propose the establishment of an intermediate king- FIG. 8. Voh-ox globator. dom, in which those intensely interesting, and other forms of life, should be included. While, how- ever, the naturalists are disputing, let us examine the wonderful forms before us. They are, as their name implies, revolving globes ; each sphere containing within it a number of other similar, but only partially developed, smaller spheres or globes. 50 VIGNETTE $ FROM INVISIBLE LIFE. The whole compound organism, rolling and re- volving in the water, forms a picture which once seen is never forgotten. We call them plants, for they are mostly green, and have but few of the characteristics of animal life. "Yet," you say, "they move." Yes, they are motile plants ; and if examined a little moro closely, are seen to be covered with fine cilia, or hairs, which by their vibrating action are sup- posed to be the cause of the revolving motion observable. We have probably here a promi- nent instance of the active agency of sunlight on the vegetable world. These special forms not being attached to the earth, or, indeed, to anything whatever, but only suspended, as it were, in a medium which by its elasticity does not offer suffi- cient resistance to keep it in one position and this aided by the peculiar globular form of the plant and its hair-like appendages the sunlight, which in other fixed and stable forms produces an expan- sion of growth, is here partially expended in pro- ducing this revolving motion. It is a matter of common observation that all vegetable life seeks the light or is attracted by it. It EVOLVING PLANTS. 51 Xow, if a number of these vol voces be placed in a glass jar, they will sink to the bottom when in darkness, but in the light will all arise and con- gregate together against the side where there is most light. Place the jar in the sunlight and they will move to, and revolve rapidly on, the bright side. The motion of these bodies thus appears to be due to a combination of causes the globular form, the vibratile cilia, and the sun. The cilia here referred to is a matter of great interest, and worthy of attentive study. Let us try to understand it. Looking now at one of those globes under slight pressure, so as to keep it in one place, and with a high magnifying power, we see that the entire surface of the sphere is covered with a network of cells, each cell being hexagonal (produced by mutual pressure) in form, and each one attached to its neighbour by a very fine thread which runs straight across from cell to cell. The attachment is not at the angles, or by the sides of the hexagons, but by the delicate threads which cross the interspaces between. The whole membrane of the globe is thus seen to be so many distinct cells, held together by this thread-like attachment. As 52 VIGNETTES FROM INVISIBLE LIFE. the globe grows and expands, those threads are stretched to their utmost limit, and finally a breach is made in the membrane ; and thus the now matured inside globes make their escape or exit, and commence an independent existence, repeating in their life -history that of the parent form. From the centre of each hexagon are produced two fine filaments, or cilia, which, being projected on the ex- terior surface and set in motion, cause the globe to revolve on its own axis. It should be noted that these threads, or cilia, are simple extensions of pro- toplasm, or living matter, which is either moving or lying quiescent, in accordance with the require- ments of its environment. The hexagonal cells are the source whence new spheres are formed ; but only a few in each sphere are selected for this purpose, and those beginning first to show certain slight differences such as flattening out are readily distinguished from their surrounding neighbours, and their subsequent de- velopment traced. Soon this flattened cell is seen to double, but not actually to divide or separate ; next this double cell is multiplied, and we have a group of four. These are now separated from the original 11EVOLVING PLANTS. o3 cell- wall and lodged in the general cavity, where they continue to multiply in this geometrical ratio ; and, joined by others similarly conditioned, now develop the fine cilia and revolve within the original revolving parental sphere. Not only so, but another generation is generally commenced within these, before the ever-expanding outer sphere bursts or is gently opened. We have thus in each plant, globe within globe revolving ; and when you get a number together pure green and transparent each one revolving in its own orbit and carrying similar revolving globes within themselves, and the whole moving without confusion or collision gracefully through the still, clear water, you have almost a miniature of the solar system under your gaze. If you have a vein for poetry, the contemplation of the hidden beauty of this little plant, thus revealed to your senses, is enough to awaken it. But this is not all ; within those globes are often seen veritable live animals small rotifers, each one having a complex organisa- tion. They are free-swimming creatures ; and as they move through the hollow sphere of the Yolvox you can trace their mode of life, &c. I have often 54 VIGNETTES FllOM INVISIBLE LIFE. seen half-a-dozen within one Yolvox sphere, and watched their depredations for, however they may get there, there they are, and must eat to live ; and so the young, half -developed Yol voces become their prey, and the whole globe is some- times spoiled and rendered unproductive by these little parasitic depredators. During the summer the Volvox ylobator continues to propagate, as above described, by self-division or multiplication ; but by the autumn two new kinds of- cells make their appearance within the parent globe. These are larger than the ordinary ones, and do not divide or, rather, only one of them docs : and tliis is in a totally dissimilar manner to the usual plan. The new cell thus referred to is the male or sperm cell, which, instead of dividing into globes, simply develops itself into flat discs, and, losing the green matter, is transformed into red or yellow, and eventually appears as an elongated cell, with a red eye-spot and two long cilia. The other of the new cells is the female or germ cell, and does not divide. It is at first pear-shaped, but finally becomes globular and enveloped in a glutinous membrane. As this operation becomes perfected, the sperm cells DEVOLVING PLANTS. 55 break up into a number of antherozoids, as they are now named. These are free and rapidly swimming animal-like bodies, and assembling round the glo- bular gynogoinidia, or germ cells, penetrate the soft gelatinous envelope, and coalesce or are absorbed in them. Thus is formed the winter cell, or egg, which sinking to the bottom of the water, and remaining in this condition during its hibernation, is destined to become the progenitor of another generation. In the spring this egg or spore becomes swollen, breaks, and the contents, consisting of small cells, are pro- jected into the water. Here they soon begin a geometrical method of propagation dividing first into two, then four, eight, and sixteen combined bright-green cells, each with its two filaments of active cilia. So is formed the new plant, destined to repeat in its own history all the interesting phenomena of its ancestors, as already described. There is yet another phase in the history of this interesting organism. At certain stages some cells lose their vegetable character altogether, and become animals, closely resembling Amwbce a little bit of formless protoplasm, moving hither and thither by throwing out prolongations, or limb-like projec- 56 VIGNETTE 'H FROM IX VISIBLE LIFE. tions of its body, in whichever direction it chooses to take. No merely written account can adequately con- vey to the mind the exquisite beauty and graceful motion of these pure green symmetrical and trans- lucent spheres. They are sometimes found in great abundance in rather shallow ponds and ditches, and are always objects of great interest to the beholder, especially when it is considered that all the phe- nomena here described (and much more) are included in an organism just discernible by the keenest vision unassisted by the microscope. VII. LIVING- MATTEE. " Tlie addition of matter from year to year arrives at last at the most complex fonus ; and yet so poor is Nature with all her craft that from the beginning to the end of the universe, she has only one stuff but one stuff with its two ends to serve up all her dream-like variety." EMERSON. THERE are simpler forms of life than even the Amoeba, but few more curious and interesting. If some pond- water is put into a bottle and allowed to settle, the object we are in search of will probably be found in the sediment at the bottom. A drop of this should be gradually allowed to fall from a dipping-tube on a glass slide, and then, being covered with a thin glass cover, placed on the stage of the microscope for examination . If we are fortunate, we shall see a very fine bit of almost clear, jelly-like matter, of irregular outline ; and on observing it attentively for some time, we shall remark a withdrawal of some portion of its jagged 58 VIGNETTES F1WM INVISIBLE LIFE. form, and a projection of others in different directions. At first sight you would think the little organism under your gaze had burst. But you are soon con- vinced that this is not so, as a similar motion is seen going inwards ; and by its expansion in one FIG. 9. Amtelxc. direction and contraction in another the whole mass, or animal, is moved forward. This is its method of locomotion. These projections of its substance are named pseudopodia, or false feet, which, however, are more like gloved fingers than feet. Yet, such as they are, they are extemporised as often as required now in one direction and now LIVING MATTE It, 59 in another. Although the actual form of these projections does not differ \ery much, yet, by their appearing at different places, they cause the whole body to change its shape so constantly as to gain for it the name of the Proteus animalcule. By this method of projection it not only moves from place to place, but also takes up the food it re- quires. We may say truly that it makes a foot or a hand as often as it requires either, whether to feed or move. As to its feeding, you will see one of these finger-like processes come in contact with something suitable to its sustenance ; when it will quietly roll over it, and so [absorb or draw it into its own substance and digest it. It also sometimes undesignedly multiplies itself by this means. Thus a finger or a lobe is thrown out too far for its owner to draw it back again. In this condition the lobj acquires a thickening and widening at its extreme end ; and the effort of the parent body to draw it in produces such an attenuation of its intermediate substance that it ends by being de- tached from it altogether, and so a new Amoeba is formed. As a rule, however, this process of multi- plication by fission or self -division, so common in 60 VIGNETTES FROM JM'lSUiLE 1<1FJ<;. all the lower forms of life, is performed in a regular and methodical manner. In order clearly to under- stand this process, another very simple yet impor- tant part of the structure of the Amoeba must be observed. This is seen in the sketch as a mere dark spot. It is the nucleus. Within it, is also seen another small dot named the nucleolus. These are the germs of future generations. The power and potentiality of life is stored carefully here ; and consequently when a division is to take place a portion of this important matter must go along with each half. When fission is about to occur, a con- striction, slight at first, is seen going on on each side of the main body of the Amoeba, which gra- dually increasing, at length embraces the nucleus ; the nucleus then divides, giving half of its contents to each part, and resuming in each its perfect form and function. The appearance now presented is that of two Amoebae, just linked together by an ever-lessening tie ; and this finally parting asun- der, the two forms pursue (each one for itself) its own independent existence. This is the usual method. Another has been observed when a gelatinous cyst is formed, enclosing the whole LIVING MATTE 7? . 61 body, and swarm spores are seen to issue from the nucleus. There is another part of the structure of this curious creature which must be noted, as it is pro- bably very important, though its exact function, as observed in this and other similar forms of life, has not been as yet exactly determined. A little white speck is seen in the woodcut of about the same size as the dark one. This is the contractile vesicle ; and it is very curious to see how it, as it were, opens and shuts. The opening or expanding motion is very slow : a little clear space is seen, which gradu- ally enlarges until, attaining its maximum, it begins to fade away, and suddenly collapses or shuts up as if with a spring. In a moment or two it begins to open again, and so on, expanding and contracting. This is probably a respiratory or circulatory motion of a very rudimentary character, and perhaps is to keep up the proper supply of oxygen required by the animal. The only other thing about the Amo?ba that can be called structure is the membrane which envelops its whole body, and which is so thin and trans- parent that the microscope fails to reveal it, and its itt VIGNETTES FTtOM IX VISIBLE LIFE. presence therefore is ascertained only by chemical re-agents. The Amoeba, consequently, is not all pure protoplasm, and must take its rank among organic structures : it approaches the dignified position of a true cell, and is fairly on its way to higher grades in the animal creation. In fact, it has already reached a higher grade ; for here are true Auuelxe (Arcella and Diffliiyici) enclosed in something more than an invisible membrane. These have something so dense to protect them that it may be called a shell. Arcella and Diffluyia are testaceous Anmbcs ; the former having a horny covering, and the latter an envelope made of particles of sand, shell, and so forth, cemented into a sort of pitcher open at one end, whence the "filmy fingers " of its inhabitant protrude in search of food. The home of the Arcella is egg-shaped, and delicately marked with a minute and regular pattern. We thus approach one of the most wonderful operations of nature, and one which is still involved in much obscurity namely, the formation of shells, or rather the marvellous form, markings, patterns, and appropriate colours which are produced under this name. Curiously enough, LIVING MATTER. 63 within certain limits, the more simple the organism the more beautiful is its shell or shield. Any description of these creatures is hardly complete without some reference to their size. The naked Amoeba figured at the head of this paper range from -soVoth to T oth of an inch in diameter, and are of such extreme tenuity that they are not in the least incommoded by being placed in a compressorium that is, pressed between two thin pieces of glass with a drop of water, in which they move with perfect freedom. VIII. ANIMATED TEUMPETS, HATS, AND PUKSES. " Where the pool Stands, mantled o'er with green, invisible Amid the floating verdure millions stray." THOMSON. THE Stentores are among the most prominent forms of Infusorial life. They are of various forms, sizes, and colour ; and few objects are more beautiful and attractive to the amateur microscopist. They are, moreover, easily found and recognised, and once seen are never forgotten. The sketch represents a group of Stentors, green and white. When expanded they arc trumpet-shaped, very much like the old " post- horn " of former times the expanded end of which will represent the head of the Stentor and the remainder its tapering body. This thinning- out of the body is very singular, for it is not a ANIMATED TRUMPETS, HATS, AND PURSES. 65 pedicle on which the animal is attached, as in some other forms, neither is it a tail : and yet this attenuation answers all the purposes of both, and many others ; for by reason of it the creature can like Milton's Imps contract itself from its FIG. 10. Steiitorvx. otherwise giant extension to an infinitesimally small compass, and again expand at will to its normal length, 1-25 of an inch. Also, by this means it enters the condition of social life. A number will thus congregate together and form a social colony, each one secreting a viscid substance by means of which they attach themselves in groups to any object. Thus, if you collect a number and F 66 VIGNETTES FROM INVISIBLE LIFE. place them in a glass jar or vase with a few sprigs of living plants, in a few hours they will be seen hanging in graceful clusters, head downwards, from the plants, the sides of the glass, or any other object near ; and being thus grouped and extended to their full length, may be seen with the naked eye or with a hand-glass. In this way one may form an ornamental object for the table of great interest and beauty. Not all Stentors, however, are thus trumpet-shaped. One fine spring morning I was walking with a friend through a part of Epping Forest, when we came upon a pond covered with what looked like the sooty deposits of smoke with which London householders are only too familiar ; and the illusion was confirmed by these masses of " blacks " being drifted by the wind to the sides of the pond, and in ridges against any obstructing substance. Observing this, my friend remarked on the condition of the London atmosphere, and the distance these deposits must have been car- ried for the water so far out to be thus polluted. I had, however, seen a similar state of things before, produced by well-known animalcules ; so dipping ANIMATED TRUMPETS, HATS, AND PURSES. 67 my bottle in the water, I held up to view, with a pocket lens, thousands of active rolling dark bodies. These were the Stcnlores niyri, of various shades of colour, intermediate from black to blue. So nume- rous were they, too, that on dipping your hand in the water it would be withdrawn all covered with them ; and on rubbing your fingers together they would be stained as if with black ink. Viewed under the microscope, these little Stentors are like so many " animated hats " (one familiar form of which they much resemble) tumbling and rolling about in wild delight. Both they and all the race of Stentors are covered all over with fine hair, or cilia, which, vibrating with life, enable them to perform such evolutions. There are some Stentors which approach to a higher form of life, in that they surround the lower part of their tapering bodies with a gelatinous sheath or case, in which they take refuge on the slightest alarm, or when the surrounding fluid gets dry ; they thus manage to retain vitality for some extra time. This power to secrete a mucous - gelatinous covering is of essential service at a certain period of their lives, when the important 68 VIGNETTES FROM INVISIBLE LIFE. operation of self -division has to be performed. This division is either oblique or longitudinal, and must embrace portions of the band -like nucleus with which they are endowed, and which, as in the AiiKL'ba, seems to embody the prime essentials of life. They have also a large contractile vesicle, which opens and shuts with regular pulsations. Around the crown, or expanded trumpet-formed head, the cilia appendages are longer than else- where, and are wreathed or coiled spirally around it, forming a very beautiful outline. A vascular canal traverses this coiled expansion, and with the long fringing cilia extends down one side the body in a gradually diminishing channel. Occasionally one gets a glimpse right down the widely expanded gullet, and observes the food passing into the several sacs or cavities which line the intestinal canal, and which were at one time considered to be so many stomachs ; and accordingly the Stentors, along with many other similar organisms, were classed as Poly gastric, or many -stomached animals. The lowest of mankind who live to eat are matched by the simplest forms of animal life ; the difference being that whereas in the former a certain ANIMATED TRUMPETS, HATS, AND PURSES. 69 degradation ensues, in the latter the result is an undoubted improvement, both in appearance and capacity. The Stentors feed incessantly ; and if with bright green algae, will so improve in beauty as to become objects of great attraction. The Stentor polymorphous has, as its name im- plies, the power of changing its form ; and, from being trumpet- shaped and attached in pendant clusters to some water-plant, it will detach itself and assume the form of a " thimble," open at one end and rounded and closed at the other, and in this form leads a free and active life, moving rapidly through the water. Their bodies are A r ery plastic, and change rapidly now gliding along in a shape- less lump at the bottom of the vessel, and anon, perched trumpet-formed on the head of another brother horn, appears as if blowing a blast or in stentorian voice delivering a message. Again a change, and they are all off, like so many animated tailors' thimbles : until, tired and weary, they resume their normal form, and are seen, grouped in clusters, hanging from a neighbouring bough. Closely allied to the Stentors are the Bi(rsarin