/ 1 
 
THE LIBRARY 
 
 OF 
 
 THE UNIVERSITY 
 OF CALIFORNIA 
 
 PRESENTED BY 
 
 PROF. CHARLES A. KOFOID AND 
 MRS. PRUDENCE W. KOFOID 
 
 mmm 
 
VIGNETTES 
 
 FROM 
 
 INVISIBLE LIFE 
 
VIGNETTES 
 
 FROM 
 
 INVISIBLE LIFE. 
 
 JOHN BADCOCK, F.E.M.S, 
 
 REPRlXTElt, WITH AUDITIONS, FROM "TIIK ,sT. JAMXS'S GAZETTE. 
 
 CASSELL & COMPANY, LIMITED: 
 
 LONDON, PARIS $ NEW YORK. 
 
 1883. 
 [ALL KIGHTS RESERVED.] 
 
&2<r 
 
 Lilo - 
 
 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 
 
 M353525 
 
viii PREFACE. 
 
 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 which 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 w r ealth ; 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 love of Nature works, 
 And warms the bosom ; till at last, sublim'd 
 To rapture and enthusiastic heat, 
 We feel the present Deity, and 1aste 
 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 
 
 Limnias, Cephalosiphon. 
 (Ecistes, &c. 
 
 V. CRYSTALLINE VASES AND THEIR INHABITANTS . 36 
 
 Floscule. 
 Stephanoc&ros. 
 
 VI. REVOLVING PLANTS 48 
 
 Volvox globator. 
 
xii CONTENTS. 
 
 PAGE 
 
 VII. LIVING MATTER 57 
 
 Amoeba. 
 
 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 " CROWNED HEADS " 123 
 
 Megalotrocha, Lacinularia. 
 
 XV. A SUBAQUEOUS CITY . . . . .139 
 
 Sponges. 
 
 XVI. NATURE'S JEWELS 157 
 
 Diatoms. 
 
VIGNETTES 
 
 FROM 
 
 INVISIBLE LIFE. 
 
 I. PLANT ANIMALS. 
 
 " Joy you iii fairies aiul in elves ? 
 We are of that sort ourselves." CAMPION. 
 
 " Full Nature swarins with life ; ouo 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 
 B 
 
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. Charchesinm 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, with 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. 7 
 
 and is a very charming thing to see. The birds, 
 of course, are an illusion ; but on one of the 
 species Zootliamnium arbmcula 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 Zootliamnium 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. BEVOLVma 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. 
 
REVOLVING ANIMALS. 11 
 
 ponds in question are not very pretty objects, the 
 reason for this anxiety on the part of naturalists 
 must be 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 volvox, of which we print a 
 
 FIG. 3. Conochilus rolvoz. 
 
 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 be bought), 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, 
 Rotatoria 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 Eotifers. 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 
 the 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 game 
 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. Eemark 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-MAKEE. 
 
 " 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." EMERSON. 
 
 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 BRICK-MAKEli. 19 
 
 interesting animals in' their 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 Meliceitane. 
 
 group have collected, and huilt 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 VIGNETTES 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 alga? 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 setse or 
 bristles : these are feelers or antennse, 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. rinyens, which 
 
26 VIGNETTES FROM INVISIBLE LIFE. 
 
 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 
 Moscules in No. V. To return, " Melicerta 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. ringens, but with more 
 of a "butterfly" character when expanded, and 
 having two long antenna. Moreover, the eyes even 
 in the adult form are more readily seen than in 
 M. ring ens, 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. 
 
TUBE-DWELLING EOTIFEES. 
 
 "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 ringens (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 ens : 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 FHOM 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 sesophagus, 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. 31 
 
 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 
 Rotifer a, 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 
 
 liesion thereto of foreign matter. When completed 
 it is cemented to a firm support, and is no part or 
 attachment of the body 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 (Ecistez, Cepha- 
 losiphon, and others all tube dwellers and bearing 
 a strong family likeness to each other. The differ- 
 ence between Limmas and (Ecistes consists princi- 
 pally in the character of the rotary organ, which 
 in the former is $/-lobed, and single in the latter ; 
 while in CepJtalosipkon there is an additional 
 attraction in a curious syphon -like projection, 
 the use of which seems to correspond to the 
 antennae 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 
 "E. M. S. Journal" for December, 1878, as a 
 new form, and obtained the name (Ecistes umbel/a, 
 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. 
 
 13 
 
V. CEYSTALLINE VASES AND THE1E 
 INHABITANTS. 
 
 "If we consider plants and animals in their most imperfect con. 
 dition, they can scarcely be distinguished. But this much we can 
 say, that the creatures which by degrees emerge as plants and 
 animals out of a common phase 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 with 
 this infinite variety, and are under no temptation to 
 twist and distort what we see to make it fit into 
 any theory. The great drawhack is the almost 
 hewildering 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. Floscnlaria i-ampamrtata. 
 
 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 Floscule 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 setae, 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 Rotifera, 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 t 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 THEIH 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. 
 rinyens, 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 arid 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 to live and thrive, though not 
 so abundant as some of its better- clef ended 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 setae, 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 Stephanoceros eich- 
 hornii. We take this creature out of its native 
 
 FIG. 7. S 
 
 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 now 
 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 operalion of its unfolding. The egg 
 
CRYSTALLINE VA8E8 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 fiower 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 born, 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 
 
4ti 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 right 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 and 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. 47 
 
 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. Now it is weary ; life seems 
 ebbing away ; and so, resting on any support in its 
 way, it appears to fall into a state of coma, or death, 
 like repose, during which the wonders of its perfect 
 nature are being matured, afid from which this 
 minute organism emerges to vigorous life. 
 
VI. BEVOLVING 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 fcirks each form within 
 
 Beckons to spirit of its kin ; 
 
 Self -kindled every atom glows 
 
 And hints the future which it shows.'' EMERSON. 
 
 THE Volcoos globator 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 Fblvocinete, 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. Volvox 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 VIGNETTES 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 more 
 closely, are seen to he 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. 
 
REVOLVING PLANTS. 51 
 
 Now, if a number of these volvoces 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 
 E 2 
 
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 
 
REVOLVING PLANTS. 53 
 
 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 
 
51 VIGNETTES FROM 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 Yolvoces 
 become their prey, and the whole globe is some- 
 times spoiled and rendered unproductive by these 
 little parasitic depredators. 
 
 During the summer the Volvox globator 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 does : 
 and this 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 
 
REVOLVING 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. 80 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 dmcebce a little bit of 
 formless protoplasm, moving hither and thither by 
 throwing out prolongations, or limb-like projec- 
 
56 VIGNETTES FROM INVISIBLE 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 MATTER. 
 
 " Tlie addition of matter from year to year arrives at last at the 
 most complex forms ; 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. 
 
 Tn EKE 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 FltOM 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. Amceba. 
 
 i 
 
 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 MATTER. 59 
 
 in another. Although the actual form of these 
 projections does not differ very much, yet, hy 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 
 undesigiiedly 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 
 lob 3 acquires a thickening and Avidening 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 VIGNETTED FROM INVISIBLE LIFE. 
 
 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 Amreba 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 
 
62 VIGNETTES FROM INVISIBLE 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 Amoeba (Arcella and Dijflfagia) enclosed 
 in something more than an in visible membrane. 
 These have something so dense to protect them 
 that it may be called a shell. 
 
 Arcella and Diffluyia are testaceous Amoeba ; 
 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 MATTElt. 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 Amcela figured at the head of this paper 
 range from -g-oWth to rsoth 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 PUESES. 
 
 " 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 are 
 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 PUltSEti. 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. ^teutons. 
 
 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 w r alking 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 ni(/ri, 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 
 
08 VIGNETTES FROM INVISIBLE LlFti. 
 
 operation of self-division lias 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 
 Amoeba, 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 6f 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 very 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 Bursarina. 
 They are not, however, trumpet-shaped, but pouched 
 
70 
 
 VIGNETTES FROM INVISIBLE LIFE. 
 
 animalcules, or rather compound purses, for this 
 purse -form is not confined to their exterior; the 
 internal digestive cavities are little cells or pouches, 
 attached by " short stalks " to the alimentary canal, 
 
 FIG. 11. Bursaria truncatella. 
 
 and are capable of receiving and digesting large 
 quantities of food, both animal and vegetable. The 
 large aperture named a mouth in the Bursaria 
 truncatella is lined with cilia, as is also its 
 entire body, interior and exterior alike. Indeed 
 the whole body is one delicate ciliated membrane or 
 cell, in which are hung sundry digestive pouches ; 
 and the creature seems formed with a view to the 
 
ANIMATED TRUMPETS, HATS, AND PURSES. 71 
 
 consumption of as mucll food as possible. The food 
 in each pouch is seen to be surrounded by a clear 
 liquid, which the celebrated German naturalist, 
 Ehrenberg, considered to be biie. Such a creature 
 may well be called Poly gastric. 
 
 The quantity of decomposing matter consumed 
 by these and all the Infusoria must be very great, 
 and the purpose served by them in the general 
 economy of nature very important; for, besides 
 acting as scavengers and keeping the waters com- 
 paratively pure, they "arrest the fugitive atoms" of 
 organic matter in their journey back to the mineral 
 kingdom, and bring them again into the realm of 
 food-forming material i.e., their own bodies, 
 which, by their amazing power of increase, furnish 
 the material of life -tissue to the higher and more 
 complex animal world. Thus man himself be- 
 comes indebted to these humble beings for the 
 abundance of his food- supplies. 
 
 The Bursars, like the Stentors, are endowed 
 with a nucleus and contractile vesicle, and propagate 
 by self-division, and also by means of internal germs 
 or embryo. One very striking feature in the Btir- 
 xarinte is the extreme delicacy of their bodies. 
 
72 VIGNETTES FROM INVISIBLE LIFE. 
 
 Though comparatively large in their general outline, 
 being about 1-1 5th to l-25th of an inch in diameter 
 and just discernible by the unaided eye, they are of 
 such extreme tenuity -as scarcely to bear the slight- 
 est touch, and, being extremely active, are thus very 
 difficult beings to manage under the microscope. 
 You want to stop its gyrations in order to examine 
 its organisation, and having so large a creature to 
 deal with, apply a gentle pressure to the covering 
 glass with this object. Now, unless you are very 
 gentle indeed, you find the Bursar has outwitted you, 
 and disappeared in a thin cloudy mucous film. After 
 many attempts you may succeed, and then are well 
 repaid for your trouble, for these animals furnish 
 the finest examples of ciliary action it is possible 
 to imagine. 
 
 Like the individual, the whole lot in a locality 
 will sometimes vanish suddenly and simultaneously 
 (Bursars and Stentors alike) ; and, " like the base- 
 less fabric of a vision faded, leave not a wrack 
 behind." 
 
IX. HYDKA. 
 
 " Great Nature is more wise than I. 
 I will not tell you not to weep." TENNYSON. 
 
 "Nature is always consistent, though she feigns to contravene 
 her own laws. She keeps her laws, and seems to transcend them. 
 She arms and equips an animal to find its place and living in 
 the earth, and at the same time arms and equips another animal to 
 destroy it." EMERSON. 
 
 OF all the minute forms of animal life, perhaps none 
 have excited more general interest and curiosity than 
 the Hydra, or fresh -water polype, and this not so 
 much from any special beauty in it, as from the truly 
 wonderful properties belonging to its extremely 
 plastic nature. To recite a few of these is enough 
 at once to arrest the attention. What will be said 
 to the following well- vouched -for facts ? You may 
 take a Hydra and cut off its head and engraft it on 
 another; or you may exchange heads one Hydra 
 with another. You may cut up one animal into 
 forty or fifty pieces, and each piece will become a 
 
74 VIGNETTES FROM INVISIBLE LIFE. 
 
 perfect and completely formed Hydra ; or, take a fine 
 lancet and cut lengthwise from head to base, just 
 leaving the latter united, and you have a double- 
 headed Hydra with but one base ; or reverse the 
 process, cutting from the base upwards, just leaving 
 the head untouched, and you have a single -headed 
 animal with a double body. What will the anti- 
 vivisectionists say to such operations as these ? 
 They may, however, take some comfort from the 
 fact that even when the head is thus halved the 
 arms belonging to each portion continue their opera- 
 tion in seizing their prey as if nothing whatever 
 had happened ; and the inference is therefore that 
 not much, if indeed any, pain has been inflicted. 
 So you may continue to play with this curious 
 animal, and stuff one end of the body of one into 
 that of another, and behold the two unite and form 
 one hydra. It is even said although some recent 
 experiments throw doubt on the assertion that, 
 if with a fine bodkin the animal is turned inside 
 out, it will perform its digestive function just as 
 well as it did originally the other way. 
 
 When the Hydra is expanded, with its tentacles 
 hanging gracefully down, as in the wood-cut before 
 
HYDRA. 75 
 
 us, it is rather a pretty object ; but if one casts 
 about for a similitude it is rather difficult to find 
 one. The knotted cat-o'-nine-tails supplies a not 
 inapt comparison, both as to form and function. 
 A handle with knotted cord or thongs at one end, 
 
 FIG. 12. Hydra fusca on anacharis. 
 A. Natural size expanded. B. Natural size contracted. 
 
 when wielded with a strong arm and falling on the 
 back of a criminal, is said to sting ; and here is an 
 animal just of this form : a hollow or sub-cylin- 
 drical body, with from five to ten slender serrated 
 or knotted-like arms springing from its head, 
 each armed with poisonous stinging organs, which 
 spring out with marvellous velocity at the moment 
 of impact with its prey killing some at once and 
 
76 VIGNETTES FROM INVISIBLE LIFE. 
 
 benumbing others, rendering them helpless victims, 
 to be devoured at leisure. The Hydra is a voracious 
 being, and attacks and devours creatures much larger 
 and more highly organised than itself, such as small 
 crustaceans, &c. The so-called water-flea is stunned 
 by a gentle tap on its head with one of the Hydra's 
 arms, and then drawn gently to the mouth and 
 absorbed. After a while, however, the shell of the 
 Entromostracan will be thrust out, sometimes in a 
 perfect condition, the contents having been beauti- 
 fully cleared out without any injury to the exterior. 
 Small worms which live in water are a favourite 
 dish, with which the Hydra will gorge itself when 
 it gets the chance, so much so as to disfigure its 
 entire body with them. One celebrated observer 
 of the Hydra, M. Trembley, relates a contest 
 which he saw between two Hydras for the posses- 
 sion of a worm, and how it ended by one Hydra 
 swallowing the other and the worm together, and 
 having absorbed the worm in its digestive cavity, 
 quietly yielded up uninjured his troublesome but 
 weaker brother Hydra. If, however, the Hydra is a 
 good eater, it appears also to be a good faster, and 
 seems capable of existing for days and weeks to- 
 
HYDRA, 7? 
 
 gather without food. Stretching out its tentacles 
 in search of prey, and, finding none, it will gra- 
 dually accommodate itself to its abstemious con- 
 dition by diminishing its capacity, and so live on 
 till better times come round again. I have kept 
 
 FIG. 13. 
 A. Hydra vulgaris. B. Stinging organs magnified. 
 
 Hydras in this semi-starved state for a long time 
 in perfectly clear water. They have nevertheless 
 multiplied, though getting, as they say, " small 
 by degrees and beautifully less" on water diet 
 only. 
 
 There are two well-marked species of Hydra : 
 the one green, //. viridis, and the other white or 
 
78 VIGNETTES FROM INVISIBLE LIFE. 
 
 brownish, according to the nature of its food or 
 condition as to food -supply. This latter form is 
 sometimes, or rather generally, divided into two 
 species H. vulyaris and H. fusca : the former a 
 plump, well-fed, light brown fellow ; and the latter 
 white, thin, and attenuated. It is, however, highly 
 probable that the difference is entirely owing to 
 the question of food or no food ; for I have seen 
 the full and plump H. vulyaris, with its short 
 stumpy arms, too lazy to extend them far beyond 
 its own body, gradually change both in appearance 
 and action as its supply of food became less and 
 eventually was cut off altogether. It then lost flesh, 
 and in the endeavour after food gradually threw 
 out its arms further and further, until it w r ould 
 equal in extent any H. fusca in this its essential, 
 or supposed essential, specific distinction. 
 
 The Hydra are composed of a soft, jelly-like, 
 cellular substance, capable of great extension and 
 change of form and colour. It is a living tube of 
 sarcode, having its principal concentration of power 
 at one end, which is regarded as the head, and 
 where is situated the only opening into and exit 
 out of this wonderful tubular body, and whence 
 
HYDE A. 79 
 
 the arms, or tentacles branch off, coiling about in 
 all directions in search of prey. The other end is 
 provided with a suctorial disc, by means of which 
 the animal attaches itself at will to floating plants 
 thus obtaining the benefit of change of position 
 without effort or to any other fixed or movable 
 object near. They are very sensitive to light ; and 
 if kept in confinement in a confectioner's glass jar, 
 one may with a hand-glass watch their movements 
 with great ease. They will collect on the side of 
 greatest light ; and if the jar is suddenly turned 
 round, the long tendrils, though hanging down 
 gracefully at the moment, will now stretch right 
 across the body of water towards the bright 
 side, as if anticipating the coming pleasure of 
 moving in that direction, which they will do if 
 undisturbed. The motion, however, is so slow, if 
 unaided by any floating object, that a few inches 
 distance takes as many hours to get over. This 
 they accomplish in more ways than one. They 
 will measure themselves by attaching the mouth or 
 a tentacle in the direction required, and then bring- 
 ing up the foot when the previous hold is dropped 
 and expanded again for another step, and so on 
 
80 VIGNETTES F1WM INVISIBLE LIFE. 
 
 until the goal is readied ; or they will turn them- 
 selves over with a bound. Another method has 
 been observed : by hanging head downwards on 
 the surface, with the foot thrown out above, and 
 thus floating with the stream. 
 
 There is very little of organisation in the Hydra ; 
 yet they are possessed of one extraordinary power 
 in their stinging organs. If one takes a Hydra and 
 places it under pressure, then with the microscope 
 will be seen a number of small oval capsules (which 
 the pressure has forced out on to the glass), with a 
 long and fine point projecting out from each, as in 
 the woodcut; and it is supposed that it is with 
 these that the prey of the Hydra is secured and 
 killed. It may be conjectured that these points 
 are coiled up within the capsule, and are used only 
 when wanted, when they spring out with force 
 enough to penetrate their victims. The sin- 
 gular effects of this impact have led to the con- 
 clusion that these capsules contain poisonous 
 matter, and this is apparently confirmed by some 
 chemical tests. A worm, which is so tenacious 
 of life that if cut in pieces each piece will live 
 a considerable time afterwards, is yet instantly 
 
HYDRA. 81 
 
 killed by the touch of the Hydra. Yet the 
 Hydra is not vicious, and kills only when it needs 
 food, and then in the easiest possible way killing 
 the worm outright, and numbing other animals so 
 that they suffer not. Although so destructive 
 when in want, it is very tolerant of other creatures 
 which it does not require for food especially so to 
 a small infusorian, great numbers of which are 
 often seen swarming over it, and are apparently 
 supported by what they get as parasites off its 
 tentacles and body. 
 
 We have seen how the Hydra may be propa- 
 gated by cuttings, and it may be here noted, that 
 those thus produced are generally the finest, as is 
 the case in so many other of the lower forms of life. 
 The general method is by budding. A slight pro- 
 tuberance will appear anywhere indifferently on the 
 side of its body, which gradually grows into a bud, 
 and thence into a young Hydra exactly like its 
 parent, to which it will remain attached for an 
 indefinite time : indeed, if undisturbed, a second 
 and even third generation will thus be formed, 
 Hydra budding on Hydra, before a detachment 
 is effected. The young thus produced eventually 
 
82 VIGNETTES FROM INVISIBLE LIFE. 
 
 sever themselves from the body of the parent, 
 and begin life on their own account. Another 
 mode of reproduction is by the formation of sper- 
 matozoa and ova. Both are formed on the same 
 body, in small conical and sac -like projections. 
 When maturity is reached, the sperm- sac bursts, 
 and the contents, becoming liberated, fertilise the 
 ovum, very much after the manner accomplished 
 by the pollen of flowers. After being fertilised 
 the ovum becomes invested with a thick and hard 
 covering, drops off, and remains thus protected 
 at the bottom of the water through the winter ; 
 and on the return of spring from these seeds 
 or eggs new Hydrce are reproduced. Thus the 
 Hydra, though differing materially from vegetable 
 forms of life, yet shows some striking likenesses to 
 them, especially in its reproductive processes i.e., 
 buds, cuttings, and covered seed which germinates 
 apart from its parent, &c. 
 
 Though not a displeasing object to the eye, but 
 on the contrary very graceful in form and motion, 
 the Hydra is yet one of those beings from which 
 the gentler sentiments recoil. Their poisonous 
 stings, their coiling arms enveloping animals 
 
HYDRA. 83 
 
 much larger and higher in the scale of life than 
 themselves and the slow yet inevitable fate at- 
 tending their movements, are all so many dread- 
 inspiring elements. If to all this is added their 
 extreme minuteness, combined with so much power, 
 there arises almost a feeling of awe in contemplat- 
 ing the tiny creature, and we see that, if not the 
 monster its fabled name implies, yet it is somewhat 
 near akin to it and its larger marine relatives of 
 which such tales of horror are sometimes related. 
 
 The Hydrce inhabit ponds, ditches, and slowly 
 running streams, and H. vulyaris may be found in 
 great abundance in the canals around London, 
 attached to algae and other fresh- water plants. The 
 common weed Anacharis, which is so prolific as to 
 have become a nuisance in our streams, is sometimes 
 covered with them. At almost any time, if one picks 
 up a little of this weed from the Eegent's Canal in a 
 bottle of water, one or more of these creatures will 
 almost be sure to be seen depending from it; and if 
 kept in a clear glass jar with clean water, the seven 
 or eight arms will soon be seen stretching out in 
 search of food. These arms will sometimes expand 
 to a length of several inches. 
 
X. WATEK-BEAKS AND BOTIFEKS. 
 
 " For nature also, cold and warm, 
 And moist and dry, devising long, 
 Through many agents making strong, 
 Matures the individual form." TENNYSON. 
 
 " Loneliness takes life 
 As over its world 
 The invisible hovers." UHLAND. 
 
 IT might be supposed that one of the most unlikely 
 of places in which to hunt for animal life would be 
 a gutter under the eaves of a house ; yet this is one 
 of the places where the " Water-bear " (figured on 
 the opposite page) was first and is often now found. 
 This can hardly be called its habitat or favourite 
 haunt, or it would not have been named Water-bear; 
 for although water is often found in roof -gutters, 
 yet it is also as often absent. The fact is that these 
 animals are here by accident, and not from choice. 
 They are here against their will, so to speak ; and 
 this circumstance leads at once to the most extra- 
 
WATER-BEARS AND ROTIFERS. 85 
 
 ordinary fact about them. They, like some Eotifers, 
 are so extremely tenacious of life that they will 
 bear drying up into (to all appearance) fine dust, 
 and in this condition are carried hither and thither 
 by the wind ; and so their being in the roof -gutter 
 is accounted for. Here they lead a fitful and inter- 
 mittent life of activity and repose, according to the 
 
 FIG. 14. Water Sear (after Slack). 
 
 fluctuations of the weather at one time dry as dust 
 and scorched by the sun, and at another active in 
 sentient life under the refreshing rain. It may be 
 presumed that they would rather be always in the 
 water ; but ponds as well as gutters sometimes dry 
 up. So they have in the course of ages accommo- 
 dated themselves to these inevitable fluctuations, 
 and are apparently well content with their present 
 lot. Not much water, however, is necessary to 
 their active existence ; for they are often found 
 
86 VIGNETTES FROM INVISIBLE LIFE. 
 
 roaming in and about damp moss as well as in 
 pools and ponds o water. 
 
 They have, however, acquired the very remark- 
 able power of sustaining life under conditions 
 which would be fatal to almost all other forms of 
 organic life ; for they will not only stand drying 
 up, but will remain in that condition for an 
 indefinite length of time ; so that having once 
 furnished yourself with some of this dry, dusty, 
 and latent life, you may send them in a letter to 
 your friend in Jerusalem, or anywhere else, or you 
 may keep them in your cabinet for an occasional 
 evening's entertainment. Thus taking this inani- 
 mate dust, and adding a few drops of water, you 
 will have the extraordinary privilege of seeing one 
 might almost say " these dry bones live." They 
 soon show signs of animate life and eventually 
 fully unfold and display all the activity of which 
 they are capable, as if no interruption to their 
 continuance had ever taken place. And in the case 
 of the Rotifers these activities are so very pleasing 
 that you will not very soon get tired of watching 
 their movements. They gradually unfold and 
 stretch themselves out, and after a few more move- 
 
WATER-BEARS AND ROTIFERS. 87 
 
 ments throw out the two little apparent wheels with 
 which their heads are crowned. These appear to 
 revolve on their own axes with great velocity, 
 and present a beautiful and interesting pheno- 
 
 FIG. 15. Rotifer vulgar u (after Ehrenberg). 
 
 menon ; for, though the revolving process is only 
 an optical illusion, it is so very like reality that no 
 one unacquainted with the actual facts would for a 
 moment suppose that it was otherwise than real; 
 and, indeed, it was many years hefore this illusion 
 was dispelled even in the scientific world, so that 
 this apparent rotatory movement obtained for the 
 
88 VIGNETTES FROM INVISIBLE LIFE. 
 
 creatures the distinctive name they now bear i.e., 
 Rotifers. 
 
 Having amused and instructed your friends with 
 this wonderful sight, you allow the water once 
 more to evaporate and place the dry dust away for 
 further use. Or you may now proceed to yet 
 severer tests; for both the little Water-bears and 
 the Rotifers, after being dried up in the way here 
 described, will bear intense heat before giving up 
 the ghost. True they will not stand boiling water, 
 yet they will stand dry heat up to 260 Fall., 
 and hot water at 118 Q Fah. They have also been 
 kept in a vacuum for thirty days, with . sulphuric 
 acid and chloride of calcium, without losing their 
 capability of revivification. 
 
 Various theories have from time to time been 
 propounded to account for these extraordinary 
 phenomena, and much scientific and even theo- 
 logical wrangling has been brought to bear upon 
 them. The Clericals on the Continent fancied that 
 here, in actual organisms under our eyes, was found 
 something like a demonstration of the doctrine of 
 the " Resurrection from the Dead." This idea 
 was strongly contested by their opponents ; and 
 
WATER-BEARS AND ROTIFERS. 89 
 
 after a variety of experiments it was proved that 
 the animals had not really been dead, and con- 
 sequently that there was no resurrection. So the 
 controversy passed into the realm of science, where 
 facts alone have any weight and causes and effects 
 are traced. As to desiccation and resuscitation, 
 the facts are as ahove stated ; and the cause or 
 " reason why " is found in other facts which have 
 been since discovered. These are, that the creatures 
 are furnished with a very tough and elastic skin, 
 and otherwise protected. In the case of the Water- 
 bears two skins, one over the other, are found ; and 
 in the Rotifers there is also a slimy secretion, which 
 hardens in drying, and forms an impervious coating ; 
 so when the drying commences they roll themselves 
 up, with as much moisture as they can contain, into 
 little round balls, cover themselves with this viscid 
 secretion, and also generally get a little vegetable 
 matter over themselves, and await their fate. There 
 is also another important factor in the case, which 
 explains why they will stand dry heat better and 
 up to a higher point than wet. Their bodies are 
 composed in great part of albuminate of soda or 
 soluble albumen ; and this substance when dried 
 
90 VIGNETTES FROM INVISIBLE LIFE. 
 
 will sustain a very high temperature without losing 
 its soluble characteristic, and is thus admirably 
 adapted as a vehicle for preserving the dormant life 
 within its folds. 
 
 The Water-bears are hermaphrodite. They lay 
 but few eggs, and these are hatched and the young 
 nourished and protected after a very curious 
 fashion. The eggs being deposited in the some- 
 what loose outer skin, and remaining there, the 
 young, if brought into life in this position, would 
 have no chance of escape but for the capacity 
 which its parent possesses of throwing off this 
 outer coil, which when the embryo is nearing 
 maturity it does. The eggs are now thrown off 
 with it ; the young are herein hatched, and thus 
 find a temporary refuge and sufficient nourishment 
 until able to provide for themselves. These little 
 Water-bears have obtained the scientific name of 
 Tardigrada because of their slow movements. 
 They are never in a hurry, and though subject to 
 such terrible vicissitudes as we have here indicated, 
 are always in good condition, fat and plump, and 
 continually grubbing among whatever rubbish 
 comes in their way. The mouth is a suctorial 
 
AND HOTlFEtiS. 91 
 
 organ, and passes on the food to a kind of gizzard, 
 where it is rendered fit for the digestive process, 
 and is then conveyed to the stomach, digested, and 
 assimilated to the various tissues of the body. 
 They are rather highly organised for such small 
 creatures, having eyes, a brain, and nervous system, 
 and may therefore be credited with some sort of 
 conscious sensation. The sketch shows them to 
 have four pairs of rudimentary legs armed with 
 claws. These claws are not, however, weapons 
 either of offence or defence, but simply the means 
 of enabling their owners to climb about with great 
 ease among the moss and plants in the water. 
 Thus seen, fat and plump, making his way slowly 
 and contentedly along, so small and yet so much 
 resembling its formidable namesake, he irresistibly 
 impresses one with a sense of drollery. 
 
 Nature presents many phases or, in other 
 words, life takes on many forms; but forms to 
 touch one's risible faculties are not very common. 
 There is something kind and tender in the droll 
 little Water-bear, and we are glad to look at it. 
 Indeed, one writer affectionately likens it "to a 
 new-born puppy or unlicked bear-cub." Some 
 
92 VIGNETTES F.ROM INVISIBLE LIFE. 
 
 considerable difficulty has been experienced by 
 the classifiers as to where they should place this 
 queer little fellow in the animal kingdom. He 
 has been bandied about very considerably, and 
 for a time found a resting-place among the 
 Eotifers. In some respects this was natural; for 
 he is generally found living along w T ith the 
 common Eotifer (R. mdyaris], is about the same 
 size (l-20th of an inch), has like it a shining trans- 
 parent outer garment or skin, and like it is subject 
 to and is capable of sustaining all the trials of dry- 
 ing, &c., to which we have adverted. But it is 
 not a Hotifer after all ; and having tried to fit him 
 into some other places without success, the syste- 
 matists have at length, as if in sheer despair, thrust 
 him among the spiders. There is, however, no 
 satisfaction in this arrangement; and while some 
 think he should lie here and another there, others 
 regard him as an anomaly, or a link between other 
 and better-known and more definite organisms 
 say between the Aracluioidae and the Annelides, or 
 the Rotatoria and the Helminthida. 
 
 Taken all in all, the little Water-bear is about 
 the most self -sustaining and independent animal in 
 
WATE&BJSAS& AND ROTIFERS. 93 
 
 this world. It will thrive upon food when it can 
 get it, or do without it for an unlimited period. 
 The kind of food is also a matter of supreme in- 
 difference to it, for it will either live on the juices 
 of other creatures or among the debris of de- 
 caying animal and vegetable matter. Pure or 
 dirty water comes alike to the Water-bear, or 
 it will do without either, and grub among damp 
 mosses for a livelihood , and, in the absence of 
 even these, it quietly rolls itself up in its own skin 
 and passes on the wings of the wind whithersoever 
 it listeth. Though of relatively high organisation, 
 it yet can do without a mate for the continuance of 
 offspring ; and these when they come give him 
 neither care nor trouble, being, as we have seen, 
 simply folded up in their parents' cast-off coats and 
 left to shift for themselves. This is just such a 
 creature as to stand the " wreck of matter and the 
 crash of worlds," and almost answers the desider- 
 atum of some scientists for a creature that would 
 bear the physical force of transference from one 
 globe to another wrapped up in some form of 
 mineral matter. 
 
XI. COMPOSITE ANIMALS. 
 
 " The man whose eye 
 Is ever on himself, 
 Doth look on one 
 The least of Nature's works." WORDSWORTH. 
 
 " We penetrate bodily this incredible beauty ; 
 Our eyes are bathed in these lights and forms." 
 
 EMERSON. 
 
 THE principal object in this sketch is a group of 
 Plum a fella, a form of fresh- water Polyzoa to whicli 
 are attached stentors, rotifers, vorticellae, and a beau- 
 tiful tree form of epistylis. As they were all found 
 together, so they are here drawn not because there 
 is any affinity between them, but merely that they 
 formed thus, under the microscope, a picture of 
 exquisite beauty and interest. Every one who is 
 familiar with microscopic life has often found 
 animals of various and diverse forms curiously 
 combined : and, indeed, it is these wondrously 
 beautiful pictures that constitute one of the chief 
 
COMPOSITE ANIMALS. 95 
 
 charms of microscopic work. The jaded clerk or 
 anxious business man, half worn-out with the cares 
 and routine of city life, is here transported to fairy- 
 land, and finds his anxieties vanish in communion 
 with the wonders of nature. Putting aside for the 
 
 FIG. 16. Ptumatella repens, with Rotifers, <S:c., attached. 
 
 time the rotifers, &c., you have a colony of this 
 singularly beautiful fresh-water Polyzoon, with 
 crescent plumes of delicate, tubular, ciliated ten- 
 tacles, vibrating with life. Eapid currents are 
 formed in the surrounding water, and the nutrient 
 minute particles whirled within the plume and 
 down the gullet to the alimentary canal, where 
 you may observe the changes they undergo as 
 they are rapidly digested and assimilated for the 
 
96 VIGNETTES FROM INVISIBLE LIFE, 
 
 creature's nourishment. These plumes are en- 
 dowed with great sensibility and under perfect 
 control ; so that on the least alarm they are 
 rapidly withdrawn, and with returning sense of 
 security are again slowly protruded, folded as 
 in a bundle, and presently expanding in all 
 their glory, resume the normal activities of their 
 being. 
 
 The general plan of organisation is much alike 
 in all the Polyzoa. A tubular ciliated canal " bent 
 back on itself " is suspended in a transparent mem- 
 branous sac, to which it is connected. It is sur- 
 mounted with the plume or crown of tentacles before 
 named, forming the head and mouth and receiving 
 the food, is endowed with all the functions of diges- 
 tion and assimilation. The enveloping sac is filled 
 with fluid matter, and furnished with nerves, muscles, 
 and reproductive functions. It also secretes another 
 membrane of greater strength on its exterior, form- 
 ing a double protection to the delicate life within 
 its folds. 
 
 It has several methods of reproduction, one of 
 which is so intimately blended with its organisation 
 that this seems the fitting place to mention it. This 
 
COMPOSITE ANIMALS. 07 
 
 is by gemmation, or budding. A small swelling or 
 protuberance is observed within the interior mem- 
 brane or sac near the apparent orifice whence the 
 tentacles are protruded. This protuberance gradu- 
 ally increasing in size, at length assumes the exact 
 form of the parent ; and though still connected 
 with it, yet commences life on its own individual 
 account, and reproduces itself in like manner. A 
 connected colony is thus formed, branching off in 
 all directions, like the little twigs of a tree. At 
 every joint there is a partial division ; so that each 
 little branchlet contains its own individual polypide, 
 as in a cell or chamber, while still united to its 
 nearest neighbour. In this way the colony is 
 formed ; and hence the name Polyzoa i.e., many- 
 lives, or compound animal is derived. In some 
 genera this process is carried still further, and a 
 second division is produced as in Cristatella and 
 Lophopm where, when the colony becomes un- 
 wieldy, a separation, not of the individuals as such, 
 but of the colonial structure, takes place : the reason 
 of these exceptions being apparently because of the 
 more delicate and softer nature of the investing 
 membranes in these than in other forms. 
 H 
 
98 VIGNETTES FROM INVISIBLE LIFE. 
 
 Another form of reproduction is that in which 
 small bodies are produced named Statoblasts (Fig. 
 17 A). They are seen lying within the inner transpa- 
 rent membrane during the greater portion of the life 
 of the Polyzoon, and have generally been spoken of 
 
 FIG. 17. 
 
 A. Statoblast. B. Young Polyzoon in process of development from a 
 
 Statoblast. 
 
 as winter-eggs. They are of diversified form in the 
 several genera and species round, oval, or oblong- 
 lenticular bodies, which furnish by their shape, &c., 
 a ready means of identification. In one instance they 
 are furnished with hooked spines projecting from 
 their margins. In all cases they are beautiful and 
 interesting objects. Generally they are lying quietly 
 and loosely within the sac investment ; but occa- 
 sionally one sees them being tossed up and down 
 
COMPOSITE ANIMALS. 99 
 
 like balls from the hands of a conjuror. There is 
 110 apparent way of their getting outside the sac ; 
 and, indeed, they never do until the parent dies or 
 some accidental rupture is made. On the dissolution 
 of the colony they escape, and may be collected in 
 great numbers from the surface of the water. They 
 are now very interesting objects of observation. 
 One might be pardoned who was not familiar 
 with them if he fancied he had a vegetable seed 
 under the microscope somewhat resembling a small 
 bean. On the approach of warm weather the 
 statoblast begins to swell and the sides open, re- 
 vealing not indeed the first tiny germ of a future 
 plant, but a small and veritable animal, with ex- 
 panded tentacles clothed in vibrating cilia (Fig. I?B). 
 As it grows, the shell-like investment is dropped ; 
 and the creature floats away in the surrounding 
 water, the destined founder of a future colony. 
 
 There is yet another method by which offspring 
 are secured ; and that is of a true sexual character, 
 through the several means and stages of ova, sper- 
 matozoa, egg, and embryo in the same individual. 
 In this instance, however, the young brood are not 
 at all like their parents, but rather resemble ordinary 
 H 2 
 
100 VIGNETTES FROM INVISIBLE LIFE. 
 
 slipper- shaped ciliated infusorians. In this stage 
 fchey are seen swimming freely about within the 
 membranous sac of the parent ; and here again, as 
 with the statoblasts, one is at a loss to understand 
 how they are to get out. The sac is closed organi- 
 cally round the two ends of the alimentary tube, 
 and any rupture of it would, by letting out the 
 internal fluid, be fatal to the creature's existence. 
 At any rate, an important purpose is served by 
 confining them for any length of time within it ; 
 for here their delicate structure is beautifully pro- 
 tected and nourished, and we see them grow and 
 pass from stage to stage of development until the 
 outline of the several adult organs are visible and 
 all seems ready for their full expansion. Yet here 
 they remain ; and I cannot find that any one has 
 ever seen them escape except by means of artificial 
 rupture of the sac. I have found them free in open 
 water, and, bottling some up once, thought I had 
 found a new species of infusoria. The microscope, 
 however, soon undeceived me, by revealing the im- 
 mature and incipient structure of a Polyzoon. It is 
 probable that they only escape or are born with the 
 dissolution of the parent, as is the case with the 
 
COMPOSITE ANIMALS. 101 
 
 statoblasts. Being free, they now pass rapidly to 
 the mature form, attach themselves to some aquatic 
 plant, produce buds, statoblasts, and embryos in 
 their turn, and so complete the circle of their in- 
 dividual and collective life. 
 
 Ee verting to the compound or colonial charac- 
 ter by which each member, though of distinct and 
 vital individuality, is yet in some non- vital way 
 organically connected with the whole, we observe 
 that the several individuals form for themselves, 
 or, more correctly, arrange themselves into, semi- 
 detached apartments or cells. Generally these 
 open one into the other, and some communication 
 is kept up between each, which is presumably 
 mutually beneficial ; but in some instances these 
 cells are partially, and in others completely, closed 
 against their neighbours. So while living under 
 the same roof so to speak social intercourse is 
 suspended, except by contact from without, when 
 the crowns of tentacles of the several individual 
 polypides are protruded together. This is not 
 always the case, for each one has the full power of 
 acting for and by itself so far aS its own indivi- 
 dual interests are concerned, except that it cannot 
 
102 VIGNETTES FPOM INVISIBLE LIFE. 
 
 altogether part company with the colonial struc- 
 ture. This compound structure is named the 
 Canacium, and is spoken of as " an assemblage of 
 little cells " or chambers, in which the several 
 members of the colony or polypides are lodged. 
 It is, however, as we have described it, part and 
 parcel of the polypides themselves, each little cell 
 or chamber being an individual polypide, though 
 united to a common whole by their investing mem- 
 branes. These colonial structures of living animals 
 are found generally attached by a viscid secretion to 
 aquatic plants : some prefer the under-side of the 
 broad leaves of the water-lily, where they spread 
 themselves in an irregular kind of network against 
 the leaf ; others twine around the stem or on bits 
 of stick or rotten wood, sometimes in large irregular 
 masses or in spindle -shaped forms of considerable size; 
 others are found twined in long branching colonies 
 along with the coarse filamentous alga? at bottom 
 of deep ponds or canals. I have found one of the 
 most beautiful and largest forms i.e., Lopliopus 
 crystallinus hanging like bright beautiful blossoms 
 on the too common Anacharis, in the clear water of a 
 shallow pond a beautiful picture even to the naked 
 
COMPOSITE ANIMALS. 103 
 
 eye. There is one form i.e., CristateUa mucedo 
 which is exceptional. It loves the light, and floats 
 about sometimes unattached on the surface of the 
 water, and at others creeps ahout on the plants. 
 Hence it is generally called the Travelling Polyzoon. 
 It does not travel fast, however, and its method of 
 locomotion is involved in some obscurity ; but as 
 the under- side consists of a contractile disc, it is 
 probably by means of its contraction and expansion 
 that it gets along. 
 
 The fresh- water forms comprise only a small por- 
 tion of the great class of animals designated Polyzoa, 
 which are mostly marine ; but enough has been said 
 to show that we have in our ponds and canals 
 a beautiful and intensely interesting variety of this 
 wonderful form of animal life ; and moreover, they 
 will bear domestication, so that one may keep up 
 a stock of almost every variety in a few glass 
 jars. Even thus seen with ordinary vision in 
 clear water, with aquatic plants, they are very 
 beautiful ; and when required they will lend them- 
 selves without injury to gentle separation with a pair 
 of fine scissors, for our more exquisite pleasure 
 and instruction under the microscope. 
 
XII. THE SUN ANIMALCULE. 
 
 " He who feels contempt 
 For any living thing, hath faculties 
 Which he has never used." TENNYSON. 
 " I am myself an irradiated manifestation of the Supreme." 
 
 RIG VEDA (Hindu). 
 
 THE Sun Animalcule i.e., Actinophrys sol, belongs 
 to a class of very remarkable animals. It consists 
 of a small bit of globular protoplasm, with spines 
 radiating in every direction from its surface ; and, 
 when seen in perfect condition for the first time 
 under the microscope with proper illumination, it 
 seems to shine "like the sun in its brightness." 
 Hence the original observers gave it the name of 
 Sun Animalcule. Indeed, any old ordinary picture 
 of the sun would do very well for Actinoplirys, as 
 conveying a general idea of its form ; though in 
 another aspect the moon would be a more appro- 
 priate symbol of its character, for it shines with a 
 
THE SUN ANIMALCULE. 105 
 
 cold and silvery brightness rather than with the 
 warm and golden rays of the sun. But of course 
 these fanciful resemblances for which we are 
 
 Fro. 18. Actinophrys sol. 
 
 indebted to the quaint imaginations of the earlier 
 observers have no real meaning in the nature 
 of things, although, as in this case, they give a 
 
 FIG. 19. AetinospJHcrinm eic/ioririi. 
 
 popular idea of the object, and thus serve a useful 
 purpose. And, viewed in this light, the Sun Ani- 
 malcule has other resemblances than that of its 
 globular form and shining rays to the sun ; for, like 
 
106 VIGNETTES FROM INVISIBLE LIFE. 
 
 it, there are at least two zones or layers namely, a 
 bright and clear vacuolar ectosarc, covering a firmer 
 clouded internal sphere, or (as it is named) endosarc. 
 Dropping further resemblances to the sun and the 
 moon, we see springing from this endosarc the 
 pseudopodal rays, which are simply extensions of its 
 own granular protoplasmic substance. These rayed 
 extensions are very delicate and flexible tentacles, 
 endowed with extraordinary pow r er. There is a 
 firm axis filament or thread starting from the body 
 forming their base, by which the creature can stiffen 
 or render them flexible, extend or withdraw them, at 
 will. All these movements are, however, very slow, 
 yet of a very pronounced and decided character. 
 When the creature requires food these spinal rays 
 are extended to their utmost length, far longer than 
 the body, and, stretching out in all directions, are 
 soon brought into contact with the more active 
 inhabitants in their neighbourhood. A small rotifer 
 or water-flea rushing past is sometimes apparently 
 impaled on their fine points, which, in the not 
 uncommon event of the struggle that now en- 
 sues, are assisted by other neighbouring spines 
 being brought to bear on and around the captive, 
 
THE SUN ANIMALCULE. 107 
 
 which is thus secured and drawn towards the body 
 of its captor. What now is to happen, for there 
 is no mouth to receive it? We have seen that 
 Actinophrys is a little roundel mass of life, with 
 nothing of apparent organisation but those rayed 
 spinal filaments, no mouth or other organs ; and 
 yet it has caught a highly organised animal, which 
 it holds in its firm embrace, presumably for the 
 purpose of using it as food. Presently a slight de- 
 pression is observed in the soft protoplasmic body of 
 the Aclinophrys, which very gradually deepens and 
 expands as its victim, the rotifer, slowly descends 
 deeper and deeper to its doom in the interior. Here 
 you may still watch it. It has ceased to struggle, 
 and sometimes even seems to enjoy its novel 
 position ; for it is accommodating itself to its 
 new environment, and sets its cilia in motion as 
 if to obtain food. Not for long, however, is any 
 motion visible. The soft parts of its body are 
 gradually absorbed for the nourishment of Acti- 
 noplirys, and the delicate shell or lorica gently 
 expelled as gradually as it was drawn in, and 
 without the slightest injury being done to it. 
 How all this is done it is impossible to say, for 
 
108 VIGNETTES FROM INVISIBLE LIFE. 
 
 there are no apparent suctorial or other organs 
 to do the work. Another and another rotifer is 
 caught, and drawn as if hy enchantment to the 
 volcano -like craters opening to receive them. I 
 have seen as many as five or six at once thus 
 absorbed, causing utter disfigurement to the body 
 of Actinophrys. There is not always a struggle, 
 and as the finely drawn-out extremities of the 
 tentacles are not visible, there is something terrible 
 in this apparent fascination, as one after another 
 of these beautiful creatures the rotifers slowly 
 wend their way to inevitable destruction. 
 
 The Actinoplirys extemporizes a mouth just 
 as the Amoeba wherever it needs one, at the sur- 
 face of its body, and where the expanded rayed -out 
 parts of its own substance happen to have come 
 in contact with a possible victim. Its body is 
 composed of granular protoplasm having cells or 
 vacuoles, which act as so many stomachs in absorbing 
 and digesting (each one on its own account) the 
 food with which it is brought in contact, and reject 
 waste products at any convenient point. Near the 
 surface of the outer zone are seen generally two 
 contractile vesicles i.e., sack-like projections of 
 
THE SUN ANIMALCULE. 109 
 
 greater transparency than the surrounding matter 
 which, after gradually swelling up to their ut- 
 most, give way so suddenly as apparently to shake 
 the whole fabric, causing a visible vibration in the 
 entire body of the animal. After a moment's rest 
 they are seen to be again expanding and again col- 
 
 FIG. 20. Actlnosphfenttni 
 In process of self -division or self -absorption. 
 
 lapsing. This process is ever going on at regular 
 intervals, and these vesicles probably serve the 
 purposes of respiration and circulation. In the 
 inner zone are observed points or cells of greater 
 density than the rest, which are termed nuclei, and 
 are probably the prime seat of life and reproductive 
 power. For it is observed that, when a certain 
 process, now to . be described, takes place, these 
 bodies, of which there are several, but never fewer 
 
110 VIGNETTES FROM INVISIBLE LIFE. 
 
 than, two, take sides, so to speak ; one goes to one 
 half and the other to the other. It is in the com- 
 mon process of self -division that this is observed. 
 One sees a slight but gradually increasing constric- 
 tion in the body of the creature, which on reaching 
 its maximum of finely drawn-out matter separates, 
 and the process is complete : the product being two 
 beings where only one existed before ; these two 
 repeating the process, and thus they go on increas- 
 ing in geometrical proportion to incredible numbers. 
 Opposed to this is another process which I think 
 may be called self-absorption, as this is its first 
 apparent result. Two individuals will approach 
 each other, and, coming in contact, will eventually 
 become so fused the one with the other as to present 
 the appearance of only one being ; the only differ- 
 ence in the appearance of the new animal being that 
 it is a little thicker or denser than either of the two 
 of which it is composed. So they or, rather, so 
 this one remains ; and no other result is seen for 
 a long time. Patience and close observation are, 
 however, eventually rewarded in this, as in all the 
 ways of life. This apparent ending, though calcu- 
 lated to throw one off one's guard, is too suspicious 
 
THE SUN ANIMALCULE. Ill 
 
 to be regarded as final. The first result of this 
 process is the partial, and finally the entire, with- 
 drawal of the rays and the darkening of the whole 
 sphere, from which it changes to almost perfect 
 transparency ; and a very delicate membrane begins 
 to surround the entire creature. Then a hitherto 
 quite unobserved body, clear and transparent, ap- 
 pears, from which emanate numerous small bodies, 
 presumably spermatoza, which, by impregnating the 
 whole mass, finally results in the formation of eggs 
 and the consequent reproduction of Adinoplirys 
 through the usual stages of embryonic life. 
 
 There is yet another method, which may be 
 called binary segmentation : it is self -division in an 
 unusual way. The spinal filaments are withdrawn, 
 and a thin gelatinous exudation overspreads the entire 
 mass. Then segmentation proceeds until the whole 
 body is resolved into a mulberry -like sphere. Each 
 component part of the berry is joined to its neigh- 
 bour, yet having its own independent life and 
 characteristic functions. On the conditions be- 
 coming favourable this covering is thrown off, and 
 each little berry-like body develops into a full- 
 growii Actinospkcenam. 
 
112 VIGNETTES FROM INVISIBLE LIFE. 
 
 We conclude this description in the words of 
 Joblot, one of the earliest observers of the seven- 
 teenth century, who, in describing this creature, 
 says : " Surely, this is a fish the most extraordinary 
 that one may see." 
 
 NOTE. Actinophrys sol and Actinophrys eichornii (or, as it is 
 now named, Actinosphcerium eichornii), being so much alike in 
 everything almost, except size, the one description applies to the two 
 forms. 
 
XIII. STAB-LIKE ANIMALS. 
 
 " Between two worlds 
 Life hovers like a star." 
 
 " And living stars to view be brought, 
 In the boundless realms of thought." 
 
 W. H. FURNESS. 
 
 THE Acinetons are radiate and suctorial infusoria 
 of peculiar interest, and on them a good deal 
 of scientific discussion has been expended. In 
 some respects they resemble Actinophrys just de- 
 scribed; and it was customary at one time to 
 associate them together. Subsequently they were 
 regarded as temporary states only in the life -his- 
 tory of other organisms, and we were favoured with 
 the acineton stages of Vortictlla, Epistylis, &c. 
 Finally, this theory was shown to be in error and 
 abandoned ; and the Acinetons were again regarded 
 as bond fide separate existences, having a family 
 
114 VIGNETTES FltniT INVISIBLE LIFE. 
 
 history all their own, which we shall now attempt 
 briefly to describe. 
 
 After long and patient watchings one becomes 
 impressed with a certain leading characteristic in 
 respect of them, and that is their variability of ex- 
 
 FIG. 21. 
 
 A. Sphcerophrya symmetrii. B. Podophrya quadripartita. 
 
 (Immature form.) 
 
 ternal form and appearance. Apparently rigid and 
 definite, they yet turn up in every conceivable ir- 
 regularity of outline, so that classification on this 
 basis becomes a hopeless task. Nevertheless, it has 
 been attempted, with the result of plunging the 
 whole subject into obscurity and confusion ; and 
 while valuable observations are made, yet the 
 charm is broken for the general reader. One result 
 
8TAK.LIKE ANIMALS. 115 
 
 of these minute divisions and subdivisions on this 
 shifting basis is the production of a nomenclature 
 which, being as useless as it is obscure, the first 
 touch of subsequent investigators generally de- 
 molishes ; but which the book-compiler continues 
 to copy and to perpetuate for the mystification of 
 those who may have courage enough to read his 
 usually costly and uninviting productions. 
 
 In some cases the Acinetons are found as ir- 
 regular lumps of jelly-like substance, clinging to 
 the filaments of algae, and covered with extraneous 
 matter to such an extent that they would be un- 
 recognisable were it not for the radiating tentacles 
 which are observed here and there branching out in 
 tufts indifferently from any part of the body if 
 we may call that body which is utterly without 
 definite form. The only thing attractive about 
 them in this state is their fine radiating ten- 
 tacles, which, in some forms, streaming out in 
 bright shining streaks of light, as it were, from 
 a comparatively dark nucleus, form a crescent zone 
 of radiating rays, and remind one of the aurora 
 borealis. In this state they will continue for some 
 time, reproducing themselves in small bright shin- 
 i 2 
 
116 VIGNETTES FPOM INVISIBLE LIFE. 
 
 ing patches, and adhering to any object with which 
 they happen to come in contact; and here the 
 variability is so great that you cannot find any two 
 alike nor, except in one instance, have I ever 
 seen any approach to definite form or symmetry. 
 This one is here represented in the wood-cut, and 
 besides being an exception to the general rule of 
 irregularity, is an apparently new form. Yet it 
 would probably be unsafe to give it a distinctive 
 name, for one may never find another like it.* 
 It has four contractile vesicles, placed equidistant 
 from each other, and exactly double that number 
 of bundles of tentacles placed at regular intervals 
 around the circular transparent body the whole 
 forming a very beautiful object. Placing this one 
 with the irregulars, as merely an exception on the 
 one point of symmetry, and proceeding to note sub- 
 sequent stages of development, it is seen that after 
 a time the tentacles are withdrawn and all active 
 signs of life are at an end. Nothing now remains 
 but lumps and shining patches of apparently pro- 
 toplasmic matter. Continuous observation becomes 
 
 * Nevertheless, as a name it must have, I have placed it with 
 the Sphoerophrya as 8. symmetric. 
 
STAR-LIKE ANIMALS. 117 
 
 irksome, is abandoned, and attention is given only 
 now and then. Suddenly a total change in the 
 aspect of affairs is observed. The dull and shiny 
 patches have alike disappeared, and in their place 
 are found the beautiful and more perfectly de- 
 veloped structure shown in Fig. 22 A. 
 
 This creature (Podophrya quadripartita) consists 
 of a bright, shining, four-cornered* star-like body 
 with radiating tentacles, perched on a crystalline 
 pedestal or footstalk, and attached to some other 
 body, usually to that on which it was previously 
 fixed ; but occasionally they are found on the shells 
 of small mollusca i.e., water-snails where they 
 are ever getting the advantages of locomotion and 
 change without any effort of their own, or they are 
 found on branches of the arborescent forms of other 
 infusorial life. In this latter position they have played 
 such pranks on the observers as to have deceived 
 some of the most eminent naturalists, and were the 
 primal cause of their own temporary expulsion from 
 the systematic records. For they planted their own 
 bodies in such an ingenious manner on similar 
 
 * They are not always quadrate or four-cornered, but vary in 
 this as in all else. 
 
118 VIGNETTES FROM INVISIBLE LIFE. 
 
 structures, that mixing up their own acineton star- 
 like forms among the ciliated cups of Epistylis, &c., 
 and other known forms, the idea was suggested that 
 the one comparatively well-known one was passing 
 though an acineton stage of being, as indicated by 
 the presence of these undoubted acinetons in their 
 midst, which seemed to be part and parcel of their 
 own organisation ; and this idea was apparently 
 confirmed by some similarity in subsequent develop- 
 ment between the two. However, as we have 
 already observed, all this was found to have been a 
 mistake, and is now given up. 
 
 Eeturning to the perfect Acineton Podophrya 
 qitadripartita we now see certain small circular 
 bodies being pushed up, as it were, gradually 
 towards the margin of the upper surface of the 
 body. (It should here be observed that in 
 these creatures there is no mouth, or orifice 
 answering to it that the body is of a granular 
 texture arid fed by suction from tubular tentacles, 
 and that out of this semi-fluid mass the small 
 bodies now observed are produced, and eventually 
 discharged.) These are free embryonic forms, 
 totally unlike their parents. Making up for the 
 
ST Alt- LIKE ANIMALS. 119 
 
 immobile parental form the young are, on the con- 
 trary, very active ; they jump and dart about with 
 great rapidity, are fringed with cilia, and may easily 
 be mistaken for other minute ciliated infusorians. 
 There is reason to think that such has been the 
 case. However this may be, let us now try and 
 watch the active ciliated body before us. This is no 
 easy task ; at last, however, one stops its gyrations 
 and rests on a bit of alga3. It is undergoing a 
 change ; the cilia disappear, and a slight projection 
 is observed at the point of greatest density, where 
 a pedicle is gradually developed. This gets fixed to 
 the weed. Now the body begins to enlarge, and 
 gradually little by little the well-known corners 
 appear, and the shining tufts of tentacles are pro- 
 duced ; and, finally, you have a mature Acineton 
 under your gaze. All this transformation is some- 
 times effected in about an hour or so. It is not 
 always, however, that the process is of this rapid 
 and continuous order. Sometimes the little ciliated 
 embryo takes a turn at multiplication on its own 
 account, and, instead of at once developing into a 
 full-blown Acineton, chooses to perform the com- 
 mon process of fission, or self-division, before pass- 
 
120 VIGNETTES FROM INVISIBLE LIFE. 
 
 ing on to the mature stage. Then two or more go 
 forward to this condition where only one would 
 otherwise have done so. 
 
 Another form of the Acinetina (Lendrosoma 
 radians) resembles a gnarled and irregular tree, 
 with stumpy branches, from which the charac- 
 teristic radiating tentacles emanate. It is rather 
 rare; and until lately its history was involved in 
 obscurity. It has now been shown that, in 
 addition to the methods already described, this 
 class is propagated by means of spermatozoa, 
 very much like that already described in Acti- 
 nophrys. 
 
 It is important to notice the character of the 
 tentacles in Acinetina as contrasted with those 
 in Actinophryina. In the latter they are finely 
 pointed spines, which pierce and draw the prey to 
 the body, where a mouth is extemporised to receive 
 it. In the former they are tubular and tipped with 
 suctorial discs, which spread a little around the 
 captured victim. Small infusorians coming in con- 
 tact with them are instantly arrested in their course, 
 and compelled helplessly to adhere, while the Acine- 
 ton draws out their soft interiors. In clear speci- 
 
STAR-LIKE ANIMALS. 
 
 121 
 
 mens you may see the fine limpid life -fluid passing 
 through the transparent tubular tentacle from one 
 body to the other. The captive is not drawn 
 towards its captor beyond the point of the tentacle, 
 
 FIG. 22. 
 A. Podophrya quadrlpartita, B. Immature form of ditto. 
 
 where it is held until all its internal juices are 
 sucked out, and what remains is simply dropped 
 from the suctorial organ and allowed to float away 
 in the surrounding water. The tentacles of the 
 Acineton are withdrawn very slowly, and apparently 
 with some difficulty. The habit of holding off 
 their prey necessitates or induces a certain rigidity ; 
 
122 VIGNETTES FROM INVISIBLE LIFE. 
 
 so, when the drawing-in process is commenced, 
 the tubular tentacle assumes a spiral form, which 
 allows of its being coiled up to a certain extent 
 and reversed on its again expanding. Thus they 
 are emptied of their contents into the body, and 
 kept always free for the suctorial process when- 
 ever opportunity occurs. 
 
 In reverting to the very variable character of 
 the Acinetina, one is somewhat helped to a compre- 
 hension by contrasting it with the same character 
 in the Annjeba. In this latter we have a small bit 
 of jelly-like matter, which, Proteus-like, changes 
 its form continually while under your observation ; 
 but in the Acineta, though the several changes are 
 probably quite as great, yet each individual, how- 
 ever much it may be unlike its fellow, rigidly 
 preserves the one form it has originally acquired. 
 Thus the changes of form which in the one 
 case takes place in the individual, in the other 
 is spread over many. The form the individual 
 Acineton gets is fixed until some important func- 
 tion of its little destiny has to be accomplished. 
 
XIV. SOCIAL "CBOWNED HEADS." 
 
 " Only so far as the masters of the world have called in nature 
 to their aid, can they reach the height of their magnificence." 
 EMERSON. 
 
 MEGALOTROCHA and Lacinularia are in some respects 
 very much like Conockilus, described in No. II. 
 There are, however, differences enough to give them 
 a distinctive character both as between themselves 
 and the latter form ; for, although they all belong 
 to the jRotaforia, and are all social in their habits, 
 living in closely -packed colonies, yet, while the 
 Cono chili are free and revolving, the others are 
 attached to the stems and leaves of plants or other 
 objects. " In Conochilus the aggregation is round 
 a central globule of gelatine, from which they pro- 
 ject like so many rays." 
 
 This is also the case with Lacinularia in their 
 free colonial condition ; and even when attached 
 
124 VIGNETTES FROM INVISIBLE LIFE. 
 
 there is this rather profuse gelatinous investment. 
 But in Mcglatrocha the aggregation is centred 
 to a fine point on a leaf or stem of a plant, 
 from which they radiate in all directions. They 
 will attach themselves thus to the glass sides of 
 
 FIG. 23. Mcgalotrocha (albo-flavicans). 
 
 a zoophyte trough, and in this condition form a 
 circular colony. 
 
 The Oonochilus is found only in ponds and still 
 water, while Lacinularia and Megalotroclia live in 
 gently -running streams. Yet, although there may 
 not he much danger of confounding the two latter 
 with the former, there is so great a likeness hetween 
 themselves, that, unless one gets acquainted with 
 their specific minute differences, they may easily he 
 
SOCIAL "CROWNED HEADS." 125 
 
 mistaken the one for the other. Further, in all 
 three there is so great a likeness in general as to 
 suggest the idea of a common origin, and to make 
 the inquiry into their affinities and into the cause 
 or causes of their divergence a subject of special 
 interest. This is one of the chief charms in the 
 study of Nature since Darwin furnished the key to 
 the inquiry; and when we find those similarities 
 accompanied with yet specific differences enough 
 to have led former naturalists to set them (as in 
 this case) in different families, one naturally looks 
 around for some explanation sufficiently feasible 
 to account for those differences. 
 
 What special circumstances, for example, could 
 have led to the formation of the free and revolving 
 spherical condition which we find in Conochilus ? 
 Presuming it to have descended from the same 
 ancestor as Lacinularia and Megalotrocha how has 
 it acquired a habit and motion so different from 
 theirs ? Or the question may be reversed, and 
 by assuming the latter to have descended from 
 Conochilus, or even both from another form 
 not present to our inquiry, still the question 
 as to the origin of the differences, and the in- 
 
126 VIGNETTED FJiOir INVISIBLE LIFE. 
 
 teresting inquiry " how acquired," remains for 
 investigation. 
 
 Presuming a common origin, why is one free 
 and revolving, and the other non-revolving and fixed 
 to a local abode r 
 
 The answer is suggested by the terms of the 
 inquiry, especially so if the difference of habitat 
 be included in it, for it is easy to conceive how 
 a comparatively slight difference in their sur- 
 roundings, caused by some accidental circumstance 
 in the first instance, may have separated the original 
 family, and given each a new environment, to which 
 it would endeavour to accommodate itself, and in 
 so doing a modification of structure or motion or 
 both (the one acting on and influencing the other), 
 would result. So an upheaval or depression of the 
 surface of the earth may have separated or cut off 
 Conockilus from its fellows, leaving it for ages in 
 comparatively still water. Under these circum- 
 stances a great advantage, or perhaps rather some 
 compensation, would be gained if a free and re- 
 volving motion such as we find it to have 
 could be obtained. It is remarkable that this 
 revolving tendency exists in both Lacinularia and 
 
SOCIAL " CROWNED HEADS." 1^7 
 
 Megalotrocha. In both the young brood is often 
 separated from the parental, surroundings, and for 
 a time lives a free rolling life, and may in this 
 condition be easily mistaken for Conochilus ; also 
 with the Megalotrocha, if a portion of even a 
 mature colony be separated and detached, it at 
 once commences, though rather awkwardly, a slow 
 and revolving motion. Indeed, a social colony, 
 whether of Rotifers or any other form of life hav- 
 ing a ciliated surface or disc, must by the action 
 of this cilia, which creates vortices and whirlpools 
 in the water, tend to produce a revolving motion of 
 the whole colony. 
 
 Nothing can be gained by this motion with 
 either Megalotrocha or Lacinularia, whose habitat 
 is moving water, and consequently we find that 
 they soon settle down to a fixed and permanent 
 attachment ; but in the case of Conoc/tilus, cast off 
 from the running stream and confined in still water, 
 this motion, by aerating the water, would be the 
 natural compensation for the loss sustained, and if, 
 as may be presumed, some sensations of a plea- 
 surable nature were added to the undoubted physical 
 advantage ; this motion would be perfected by in- 
 
128 VIGNETTES FROM INVISIBLE LIFE. 
 
 cessant application ; and would probably result in 
 other beneficial modifications of structure to har- 
 monise with it. 
 
 It should be further observed, that in the still 
 water habited by the Conoc/tilits, there is no danger 
 attending this motion corresponding to that which 
 would be the case in open running streams, where 
 such delicate bodies would every now and then be 
 in danger of transportation by floods beyond the 
 sources of their regular food supply. Hence the 
 attachment to water-plants, in the case of Megalo- 
 trocha, Lacinularia, and other allied organisms, and 
 the power temporarily to do so by other more active 
 and powerful creatures. The banks of the ponds 
 (under the water-worn and projecting edges of 
 which Conochilus is generally found) afford suffi- 
 cient refuge, when the rising waters threaten them 
 with danger in this direction. 
 
 It is thus that Nature ever works ; adapt- 
 ing herself to ever -changing conditions, and 
 evolving new forms and varieties of life and 
 motion. 
 
 In the almost infinite variety of forms which 
 life assumes on this earth there are but two great 
 
SOCIAL "CROWNED HEADS." 129 
 
 channels in which it runs. One is in an ever-im- 
 proving and progressing form. The other, retro- 
 gressive, sinking lower and lower to the dull 
 lethargic parasitic condition. Between these two 
 currents or tendencies there is, and must ever he, 
 the greatest antagonism. For the very effort to 
 improve the individual involves the improvement 
 of its environment, and thus necessitates the re- 
 moval or extinction of the parasitic class, which 
 not only obstruct, hut, as they sink lower and lower 
 in the scale of degradation, eventually become abso- 
 lutely loathsome, ugly, and repulsive, and require 
 the most energetic and strenuous action for their 
 destruction. 
 
 This is a law of life of universal application, 
 although a merciful toleration is voluntarily ex- 
 tended where the position of the better sort may 
 enable it to be done without danger ; but other- 
 wise it is ruthless in its application, being animated 
 not only by the instinct of self-preservation, but by 
 the nobler aim of arriving at the highest possible 
 physical and mental state. 
 
 We do not credit our tiny friends here under 
 description with any conscious intelligence in this 
 j 
 
130 VIGNETTES FROM INVISIBLE LIFE. 
 
 matter, or yet with any great power over their 
 environment ; yet the law here indicated is very 
 strikingly illustrated in their history ; and having 
 praised the Rotifers so much, one is glad to notice 
 that they belong, as a rule, to the improving class 
 of animal life ; so we trace a gradual and progressive 
 advance from form to form, until we arrive at appa- 
 rently the highest limit of perfectibility of which 
 they are capable : 
 
 Complex structure, having circulatory, muscular, 
 digestive, reproductive, and nervous systems. 
 
 Active in their habits, life with them seems one 
 of never-ceasing energetic motion the wonder of 
 all observers. 
 
 Beautiful in form, as with their flexuous, shin- 
 ing, crystalline, and transparent bodies, surmounted 
 with rotary crowned heads, in which are set the 
 finest of ruby-like eyes, they expand and contract, 
 and disport themselves in every conceivable atti- 
 tude, with perfect individual independence, yet in 
 mutual harmony no jostling or confusion, though 
 so closely attached ; now opening their flower-like 
 crowns in rotating or wavy motion, then withdraw- 
 ing and everting them within themselves, and again 
 
SOCIAL ' CROWNED HEADS." 131 
 
 opening and expanding ; then on the approach, or 
 in apparently nervous apprehension of danger, the 
 whole colony suddenly shrinking or collapsing, and 
 being enfolded within an hitherto unperceived 
 refuge (a gelatinous envelope, the combined pro- 
 duct, as it is now the common refuge, of each 
 individual member, always in order, and ready for 
 every emergency), and now again slowly coming 
 forth, as the sense of security returns, in all their 
 flowing, flossy, shimmering loveliness. No one can 
 contemplate them without feeling the blessedness 
 inherent in the innermost circle of Nature's opera- 
 tions, and rejoicing in perception of the meaning 
 of such beneficent tendencies. 
 
 The gelatinous or jelly-like refuge above re- 
 ferred to is a beneficent arrangement as a pro- 
 tection and defence, and also as a bond of physical 
 union. Lift from the water a sprig of the Ana- 
 charis to which these creatures are attached, and 
 you see them as minute patches or droplets of 
 jelly, which, holding sufficient moisture to sustain 
 life for a considerable period, also serves as the 
 best protection against rough usage or accidental 
 impact with hard bodies. Eeplace the plant in the 
 J 2 
 
132 VIGNETTES FROM INVISIBLE LIFE. 
 
 water, and this jelly-like substance is soon seen 
 to yield, and its contained occupants to be spread- 
 ing out their flexible bodies in radiating clusters, 
 none the worse for their temporary sojourn on dry 
 land. 
 
 For more minute examination we again lift 
 them from the water, and with a pair of small 
 scissors detach one or more of these colonies from 
 the plant to which they have attached themselves, 
 place it in a glass trough, and so on to the stage 
 of the microscope. Here, with a low power say 
 1 or lj in. objective, and with a dark -ground 
 illumination the whole colony may be seen 
 at once, and their form and motions observed 
 with pleasure and delight. They are seen to 
 be of a yellowish white colour, with soft flexible 
 bodies not divided into segments like insects, 
 but constructed in yielding, graceful folds, one 
 part overlapping the next, and easily slipping 
 into each other in telescopic fashion. The head 
 is heart- or horseshoe- shaped a crown of beauty, 
 fringed with a double row or wreath of vibrating 
 cilia, which, when in motion, gives it the rotating 
 character so much admired and so conspicuous. 
 
SOCIAL "CROWNED HEADS." 133 
 
 This vibratile motion brings the fine particles of 
 decomposing animal and vegetable matter in the 
 water to the mouth, which is situated just in the 
 bend of the heart- shaped crown, whence, by the 
 same action, it is carried down the gullet to the 
 complex gizzard or masticatory apparatus, and 
 triturated or ground down to the finest imaginable 
 pulpy material for digestion and assimilation in 
 the tissues of the body. 
 
 The trochal crown or head is not an open 
 orifice, as, from the lappet-like expansion of the 
 ciliated disc which runs round, one would at 
 first sight be inclined to suppose, but is covered 
 with a fine, gauzy, delicately-marked, and figured 
 membrane, which, at times, is gently raised above 
 the surrounding ciliated disc, as if from an up- 
 ward pressure from beneath, where are situated 
 the eyes and nerve ganglia, or brain. The most 
 prominent distinguishing characteristics in Me- 
 yalotrocha as compared with Lacinularia, are four 
 white opaque dots, placed like a row of 
 pearls around its neck. These are equi-distant 
 from each other, except at the bend in the 
 crown, just below the mouth, where the distance 
 
134 VIGNETTES FROM INVISIBLE LIFE. 
 
 between them is greater. Their function is a 
 puzzle as yet to the naturalist, though, doubtless, 
 such prominent objects serve an important purpose 
 in the economy of their possessors. The upper 
 membrane over the head is also dotted over with 
 similar, but much smaller, bodies, shining out with 
 opaline tints. 
 
 The ordinary method of viewing those creatures 
 is by means of light reflected by a mirror from 
 below the stage of the microscope through a para- 
 boloid, or spot lens, thus showing the object in a 
 soft, delicate light on a dark ground, very charming 
 and agreeable. There is, however, another plan, 
 concerning which a celebrated authority on this 
 subject recently wrote to me thus (speaking of 
 the Megalotroclia, some specimens of which I 
 had sent him) : " Have you treated it at night as 
 an opaque object, condensing a very bright light 
 from above on the group ? It is such a charming 
 object seen thus. The brilliant white spots, deli- 
 cate blue stomach, brilliant ruby spots on the sides 
 and elsewhere, and yellowish head, mastax, &c., 
 make an assemblage of colours rarely seen in a 
 Rotifer." 
 
SOCIAL "CROWNED HEADS." 135 
 
 Iii this group Megalotrocha albo-favicans 
 we seem to have reached the crown of social 
 rotatorial organisms. Individually, the size of 
 a Megalotrocha is about 1-3 6th of an inch in 
 length, a slender body, tapering off into a foot- 
 like tail, from which a sticky, gummy substance 
 unites it to its nearest neighbour and to the plant 
 or other object on which the whole colony rests. 
 It has eleven pairs of muscles, two jaws (with 
 teeth), water vascular canals, two eyes, cerebral 
 ganglia, stomach appurtenances, and reproductive 
 organs, all perfect, and in so small a compass ! 
 Yet are they the largest of all the associated 
 Rotifer a ; and, as a full-grown group expands 
 itself, one looks across their long and finely- 
 transparent bodies as through a forest of ani- 
 mated trees, the upper parts of which are dense 
 with the foliage of complex organs, while the 
 trunks are bare and transparent, standing out in 
 radiating, yet closely-compact, lines, through which 
 objects beyond are clearly visible. Of a sudden, 
 the whole forest-like colony contracts with a rush, 
 to which in imagination one may listen for the 
 sound. It is only for a moment, and again they 
 
136 VIGNETTES FROM INVISIBLE LIFE. 
 
 are extended and expanded in all their glory 
 the sovereign, yet social, crowned heads of the 
 Rotifers. 
 
 In reference to the position which the Rotifer a 
 occupy in the scale of animal life, it should he 
 noted as a fact of great significance that in 
 their history there is no intermediate or larval 
 condition after birth. All changes or metamor- 
 phoses take place in the egg, whence the embryo 
 emerges as near the exact counterpart of its 
 parents as generally obtains in the larger animals 
 with which we are familiar. There is an ap- 
 parent exception to this rule in the Floscularia, but 
 it is of a very slight and transient nature, and it 
 stands out as a remarkable fact, indicating or 
 calling attention to the general rule, and pointing 
 its importance and meaning, which may thus be 
 stated : Presuming, or taking for granted, that 
 the progress observed in, organic forms of life, from 
 very simple to very complex conditions, is not achieved 
 or produced by leaps and bounds, but is rather 
 slowly and, it may be, even painfully reached in 
 a severe struggle for existence, it follows that when 
 a creature, however small, is found having a very 
 
SOCIAL " CROWNED HEADS* 137 
 
 complex organisation (although we may not be able 
 to trace the intermediate stages or forms), either in 
 its individual development or in its tribal history, 
 yet we are warranted, in view of the general law 
 here indicated, in inferring that a series of grada- 
 tions in organic structure have really been passed 
 through before the complex organism under notice 
 could have arisen. This argument applies with 
 great force to the Rotifer a. Being so small, they 
 were originally classed with the Infusoria ; but on 
 closer examination of late years they were seen 
 to be very far removed from the Infusoria in 
 complexity of organisation, and were accordingly 
 re-classed. The gap between them, however, is 
 not filled up by known-existing forms showing 
 the several upward stages, although, when the 
 Hotlfera form is observed, this gradation from 
 one to another is easily seen and traced. Yet, be- 
 cause we cannot find the missing links between 
 the Infusoria and the Rotifers, we are not justi- 
 fied in ignoring their existence in the ages that 
 have passed away. And we thus come to con- 
 template the Rotifers in a new light, having a 
 remote ancestry, and passing through severe strug- 
 
13S VIGNETTES FROM INVISIBLE LIFE. 
 
 gles, ever upwards, and through all difficulties, 
 arriving at length, considering their minuteness, 
 at perhaps, the most wonderful perfection of any 
 known creatures . on this earth. 
 
XV. A SUBAQUEOUS CITY. 
 
 NATURA NATURANS. 
 
 " Itself surest and indescribable variety ; it publishes itself in 
 creatures, reaching from particles and spicula, through transforma- 
 tion on transformation, to the highest symmetries arriving at consum- 
 mate results without a shock or a leap." EMERSON. 
 
 ON the same plant with Meyalotrocha or Zacinu- 
 laria, one often finds small patches of whitish-gray 
 matter, looking to the unassisted eye so very much 
 like the associated groups of these creatures as 
 easily to be mistaken for them, yet no two forms 
 of life, when closely examined, are more dissimilar 
 than are the social Eotifers to this, the fresh-water 
 Sponge, i.e., Spongilla Jtuviatillis, of which we now 
 write. 
 
 Placing them together in the same zoophyte 
 trough under the microscope, the contrast is seen to 
 be very striking. Instead of a group of active 
 radiating beings in ceaseless motion, we have, to 
 all appearance, a dull cobweb-like mass of opaque 
 
140 VIGNETTES FROM INVISIBLE LIFE. 
 
 matter, from which bright and glistening thorn - 
 like bodies are projected in irregular diffusion. The 
 entire body is thus seen bristling all over like the 
 skin of a hedge -hog. 
 
 FIG. 24. Sponyilla JluviatiUis. 
 
 These thorn-like bodies or spicules, as they are 
 termed appear so embedded in the tissue of the 
 Sponge as if intended to sustain, distend, and ex- 
 pand it for a specific purpose ; and now, as we look 
 more intently, a number of small irregular openings 
 or pores, are visible, into which currents of water, 
 carrying with them fine particles of dust-like 
 material, are gently flowing. 
 
A SUBAQUEOUS CITY. 
 
 141 
 
 Presently an elevation of a finely transparent 
 membraneous nature slowly appears ; wide at the 
 base, and graduating upwards, it finally tapers off 
 into a tubular or truncated cone, from which a 
 stream of water, with contained particles of other 
 matter, is shot forth with great velocity, as if from 
 
 FIG. 25. Hypothetical Section of Spongilla. 
 
 (After Huxley.) 
 
 () Superficial Layer ; (b) Inhalent Apertures ; (e) Ciliated Chambers ; 
 (ft) An Exhalent Aperture ; (e) Deeper Substance of the Sponge. 
 
 The Arrows indicate the direction of the Currents. 
 
 the mouth of a miniature volcano, so that small 
 infusoria or other minute material coming near the 
 orifice and in the wind of the current, are caught 
 up and whirled rapidly away with it. 
 
 So far, even with the microscope, one could 
 hardly imagine this to be a living organised being, 
 or combination of animal life; for, excepting this 
 
142 VIGNETTES FROM INVISIBLE LIFE. 
 
 transparent cone -like elevation, there is no more 
 the appearance of life than even in Vesuvius itself, 
 with its rugged sides and vomiting crater. 
 
 On the principle that "wliere there is smoke 
 there must be fire," we now seek for the hidden 
 cause of this singular phenomenon, this inrush of 
 water and its rapid propulsion from an apparently 
 inert mass of matter. As we cannot see through or 
 beneath this thorny filmy covering, recourse is had 
 to the knife, and by cutting it open or taking thin 
 slices for minute examination with high powers, 
 the mystery is unravelled. Here in the interior are 
 seen small circular chambers and channels, opening 
 outwards and leading inwards, in every direction 
 through the entire Sponge body, all converging in a 
 central large cavity or chamber, and thence up and 
 through the membranous tubular elevated vent. 
 Through all these mazy labyrinths the current is 
 flowing with ever-increasing force to its final out- 
 flow. 
 
 Increasing the magnifying power, and retracing 
 our steps, so to speak, along the passages and 
 chambers of this singular structure with our now 
 more powerful vision, the hitherto invisible agency 
 
A SUBAQUEOUS CITY. 143 
 
 is revealed by which this motion is produced, in 
 a multitude of infinitely small semi-independent 
 organisms or ciliated cup-like cells, from the centre 
 of each of which is projected a comparatively 
 long whip -like cilium, which, by lashing the water 
 into ever-increasing velocity, eventually propels it 
 through all the chambers and passages and out into 
 the terminal mouth or oscule. These active agents 
 which line the walls of the passages and cham- 
 bers bear a striking resemblance to, if indeed they 
 are not exactly alike, certain classes of flagellate 
 monads which are found in associated groups as 
 distinct forms of infusorial life in great variety ; the 
 only apparent difference being that here they are 
 found with their cup-like bodies turned inwards, and 
 attached to a soft yielding protoplasmic substance, 
 instead of to a plant, in the open water. Whipping 
 the water, however, is not the only object accom- 
 plished by these ciliated zooids. As the current is 
 passed on from one to another, the nutrient matter 
 held by it in solution is absorbed by these active 
 workers, and feeds them, while the surplus passes 
 on to their nearest neighbours, to whom they are 
 attached by a physical bond. Strangely enough, 
 
14 1 VIGNETTES FROM INVISIBLE LIFE. 
 
 these, too, are, in other conditions, known as a 
 distinct class of independent bodies, which, free in 
 their ordinary localities, are here attached to each 
 other and to the flagellate cups. These neigh- 
 bours are the Amoeba described in No. VII. Here 
 in the Sponge they are found in " various stages 
 of development, constantly undergoing changes 
 of form and position. Uniting together their 
 long slender pseudopodia, they form a complete 
 net- work " of living flexible contractile material, 
 combining all the functions of nerve and muscle. 
 Not only are they thus diffused in lateral spread- 
 ing combined masses, the living basis of Sponge 
 structure, but they also multiply, and produce 
 new colonies of Sponge life, by occasional detach- 
 ments of their own substance from the general 
 mass. 
 
 The Sponge may therefore be regarded as a 
 metamorphosed Amoaba, combining in one body 
 the characteristics of the otherwise two distinct 
 forms of Flagellate infusoria and Amceba, thus 
 forming a compound and somewhat complicated 
 organism, yet having a distinct and easily-recog- 
 nised individuality, ultimately resulting in a pro- 
 
A SUBAQUEOUS CITY. 145 
 
 duct of great commercial importance. Perhaps no 
 more striking illustration could be found of the 
 truth of the adage that "union is strength" than 
 here in these two lowly, and, in their isolated 
 individuality, helpless beings, yet who, in their 
 combination, raise themselves in the scale of life, 
 and produce a structure combining all the func- 
 tions of higher and more complex organisms ; 
 having no stomach, yet perfect digestion and assi- 
 milation; no heart, yet free and full circulation; 
 no lungs or gills, yet complete aeration and re- 
 spiration ; no manipulatory organs, yet building 
 up a structure combining all the requisites of 
 strength and endurance, with the most wonderful 
 lightness and flexibility. 
 
 The Flagellate cells are apparently the most 
 active workers, while the Amoeboids form the 
 ground-work of the colony, yet also aiding by 
 their expansions and contractions in the general 
 movement of the currents through the several pas- 
 sages and the elevation or depression of the crater- 
 like vent. Nerve, muscle, and reproductive work 
 belong principally to the Amreba, as also the secre- 
 tion and development of the structureless external 
 
146 VIGNETTES FROM INVISIBLE LIFE. 
 
 investment and skeletal spicula, while the more 
 active food-collecting, circulatory, and respiratory 
 functions devolve on the ciliated or flagellate 
 monads. This combination of material and forces, 
 resulting in what we denominate a Sponge, though 
 apparently so simple, is not at all easy to under- 
 stand or to explain. Let us, then, bear in mind 
 that in this combination the two forms i.e., Flagel- 
 late infusoria and Amoeba are fused or amalga- 
 mated in one essential histological element or life- 
 tissue, which must now and hereafter be regarded 
 as one combined structure or individual animal 
 body, while at the same time each form preserves 
 its own essential function and work. This com- 
 bined oneness with semi-independence is charac- 
 teristic of all complex organisms, giving rise to 
 that general law of division of labour with unity 
 of purpose so essential to the welfare of the whole 
 body. The complexity of Sponge structure and 
 function is, however, of the simplest order para- 
 doxically though it sounds consisting mainly, as 
 we have indicated, of only two primary agents, 
 which, by their united and combined operations, 
 have succeeded in producing a very interesting form 
 
A SUBAQUEOUS CITY. 147 
 
 of life a kind of " subaqueous city " (as Pro- 
 fessor Huxley terms it), yet differing from all 
 other cities in this, that they themselves are at 
 once the inhabitants and the city -like structure. 
 
 This Sponge city, like most other cities of 
 commercial importance, is built on the banks of 
 a river, which intersects and permeates its every 
 part, bringing food, and all the requisites of 
 health and prosperity to the inhabitants. These 
 latter build themselves into over-arching passages 
 and grottoes throughout its entire length and 
 breadth, living on and over the river, drinking 
 in its life-giving element, and so completely identi- 
 fying themselves with it as to make its currents 
 perform the life functions of circulation and re- 
 spiration analogous to that obtainable by a more 
 complex method in the higher animals. So the 
 river and the Sponge go together in Sponge life ; 
 for, while the water external to the Sponge is not 
 dependent on the Sponge, its form and motion as 
 a river or running stream through the Sponge 
 city is produced by the latter, and may, in this 
 sense, be said to be so. Yet the Sponge itself is 
 absolutely and entirely helpless without the former 
 
148 VIGNETTES FROM INVISIBLE LIFE. 
 
 the river or life-current of its continuous circula- 
 tory and respiratory functions, on which its very 
 life depends from moment to moment. 
 
 Contemplating this miniature Venice -like city, 
 one feels that something more is requisite to 
 render it complete ; for, although unlike the City 
 of Waters to which we have compared it, in 
 this, that its living activities are all inclosed, 
 opening in upon themselves, and exposing only 
 their basal structure to the external world, yet, 
 even so, a defence and protection are essential to its 
 well-being and preservation. And this the Sponge 
 has not neglected ; indeed, it has made defence its 
 especial care, so that a stranger say a Stickleback 
 on approaching it from a distance, sees only these 
 defences, and, if not previously acquainted with its 
 structure, would hardly imagine it to be other than 
 a mass of prickly non-living matter. Its spicular 
 investment is composed of one of the hardest and 
 most enduring substances known, spreading over 
 and imbedded in a soft, structureless, membranous 
 tissue, which it at once upholds and protects. 
 Thus, while tenderly surrounding the living city, 
 and offering the most formidable defence to vio- 
 
A SUBAQUEOUS CITY. 149 
 
 lent enemies, it at the same time allows full 
 ingress and egress to the life-giving river which 
 runs through its midst. What more could it do ? 
 What more could we do in like circumstances ? 
 
 We do not credit the Sponge with conscious 
 intelligence; nevertheless intelligence there is 
 somewhere, and united with, or manifested in 
 and through, such a humble form of life, appeals 
 with irresistible force to something akin to it in 
 our own breast a responsive divine echo, saying, 
 " I am here also." 
 
 A very striking feature in our Sponge city is 
 the osculum, which, rising to a great height, like a 
 vast chimney built by man to carry off smoke and 
 poisonous vapours from burning furnaces beneath, 
 seems designed for a similar purpose, for all the 
 effete and waste matter of the Sponge community 
 is carried off by this exhalent funnel, and to such 
 a distance from the pores as to prevent its return. 
 
 The structure of this funnel is remarkable, being 
 composed of an extension of the membrane, drawn 
 out to the finest gossamer-like tissue, so that its 
 weight does not prevent its being carried out and 
 extended far beyond the boundary of the colony or 
 
150 VIGNETTES FROM INVISIBLE LIFE. 
 
 city. It is so fine and transparent that under 
 the microscope the river, bearing on its bosom the 
 refuse of the city, and also minute objects on the 
 other side of the tubular structure, are readily seen 
 through it. The power which raises and sustains 
 this funnel is astonishing, when the invisible 
 agencies are considered. This filmy structure, 
 distended to its utmost length and kept in position, 
 with its tubular sides almost rigid, so as to allow a 
 free and unimpeded passage to the rushing current 
 of water and refuse from the internal cavities, 
 requires such an amount of muscular force as to 
 excite our utmost wonder. It is also under 
 perfect control, and is contracted and expanded 
 at will; and in the presence of danger both it 
 and the pores are temporarily closed by the in- 
 habitants beneath. Draw off the water suddenly, 
 and this distended osculum falls over, and is raised 
 again after considerable time and labour with ap- 
 parent difficulty. 
 
 Like most of the lower forms of life the Sponge 
 has several methods of reproducing and propagating 
 its kind. One of these is by a process somewhat 
 analogous to that which is adopted in the vegetable 
 
A SUBAQUEOUS GITY. 151 
 
 kingdom by means of seed and bulbs. Certain cells 
 of the Amoeboid character are specialised for the 
 purpose, and amalgamating or coalescing, develop a 
 horny coat of great strength and endurance, and 
 also at the same time an internal spicular frame or 
 skeleton of very singular structure a " two -toothed 
 disc, like a cogged wheel united by an axis." As 
 this disc-like spiculum enlarges, the corpuscular 
 germs, or Amoeboid cells, disappear, and to all 
 appearance nothing is left but the horny coat and 
 its contained silicious skeleton. The living germs 
 are hidden somewhere, and protected during the 
 season of winter. One may here remark on the 
 nature of the seed covering horny and flinty and 
 wonder how the hidden life is ever again to make 
 its way out through such material. Certainly, 
 some vegetable seeds have very hard and woody 
 shells ; yet, even so, the germinal life would remain 
 dormant, unless planted in the earth and softened 
 by rain and dew ; but the Spongilla seed has been 
 formed in the water and made to resist its action, 
 and unless some special provision is made it must 
 remain dormant for an indefinite period. On closely 
 examining these little circular seed-like bodies, a 
 
152 VIGNETTES FROM INVISIBLE LIFE. 
 
 small pore -like opening is observed at one point, 
 and on penetrating this another is found in the 
 spicular skeleton beneath, on the axle uniting 
 them. Here the latent germinal life is interned, 
 as in a cyst, and hence it issues, when the warmth 
 of spring wakes it up. Then slowly emerging 
 thence may be seen a number of minute corpuscular 
 Amoeboids making their way into the surrounding 
 water, and eventually attaching themselves to any 
 object near, when they proceed to develop the latent 
 peculiar Sponge life with which they are charged. 
 The flagellate cells are produced, perforations are 
 made to the external water, chambers and canals 
 are tunnelled, the ventriculus, or large central cavity, 
 is excavated, the osculum is raised, the external 
 defences completed, with a bustling net-work of 
 silicious spicules ; and the new Sponge city is built 
 up and in full activity on the rushing river of its 
 own creation, the exact counterpart of its long-ago 
 autumnal ancestor. 
 
 Another method is observed in the summer, 
 when a transformation of some of the flagellate 
 cells is effected, by which they become specialised 
 into sperm and germ, or male and female units. 
 
A SUBAQUEOUS CITY. 153 
 
 The former undergo a process of granulation, and 
 become filled with small flagellate rod-like sperma- 
 tozoa, which eventually escape, and coming into 
 contact with, are absorbed by, the now mature 
 nucleated germ cells. These are thus impregnated, 
 and in this condition of a fecundated egg, pass 
 through the usual process of segmentation, the 
 contents assuming the morula or mulberry -like state, 
 followed by the external development of cilia, when 
 the egg-form embryo by its means is enabled to 
 swim about as an independent organism in the 
 surrounding water. There is no hatching process 
 of this egg. It is itself the young Sponge in 
 embryo, working out its destiny to the mature 
 Sponge city before described. 
 
 This sexual development does not seem to be 
 necessary except as a sort of more vigorous renewal 
 or reproduction, and is in consequence only occa- 
 sionally resorted to. The more common method 
 being the production of non- sexual egg-like forma- 
 tions of the Sponge tissue, which are at once set 
 free in great numbers as ciliated embryos, through 
 the osculum, and then go through the usual subse- 
 quent stages to perfect Sponges. 
 
154 VIGNETTES FROM INVISIBLE LIFE. 
 
 The Sponge is wonderfully tenacious of life, 
 and will undergo propagation by cuttings ; or it 
 will multiply itself voluntarily by the analogous 
 process of self-division, or, reversing this process, 
 it multiplies the Spongy bulk by diminishing the 
 number of individuals, by a process of fusion or 
 amalgamation with its neighbours, so completely 
 joining with each other as to leave no line of 
 demarcation to tell the curious tale. In this way 
 it becomes encrusted in large masses on floating 
 timber and the sides of docks and canals, or in 
 large globular clusters in slowly moving streams, 
 sometimes of a bright green colour, or in irregular- 
 shaped bodies of a whitish appearance, attached 
 to the stems and leaves of plants. The peculiar 
 irregularity of this last form forcibly reminds one 
 of the chalk flints, and when it is remembered that 
 these are fossil marine Sponges the coincidence is 
 interesting as incidentally furnishing evidence of 
 common origin. 
 
 One cannot speak of Sponges without at the 
 same time speaking of spicula. Yet the spiculum 
 is not an essential adjunct of Sponge life, as we 
 all know by daily experience of the toilet Sponge, 
 
A SUBAQUEOUS CITY. 155 
 
 which owes its own peculiar value to us by the 
 absence of anything hard. 
 
 The beautiful unity and harmony which per- 
 vades all nature may be illustrated in endless 
 instances; but in none is it more manifest than in 
 the intimate relationship between the living forms 
 and the mineral atoms that surround them. Thus 
 silex, lime, iron, and other mineral substances are 
 held in solution in the water (the water may be in 
 the form of ponds, rivers, lakes, seas, or diffused in 
 the earth or in the air), and in this condition are 
 always available for the uses of animal and vegetable 
 life. The living protoplasm, which is the " physical 
 basis of all life," is ever taking up and assimilating 
 this fine mineral matter into the several structures 
 which constitute its bodily frame. Animals and 
 plants alike require it, in ever- varying proportions 
 according to their kind, in the formation of bone, 
 shell, horn, hair, and other matters , and thus our 
 Sponge largely avails itself of this ever present 
 material in the construction of its spicular invest- 
 ment or embryo skeleton. 
 
 In SpongiUa the spicula are of two kinds, one 
 the amphidiscus, or double-disc cogged-wheel-like 
 
156 VIGNETTES FROM INVISIBLE LIFE. 
 
 form seen in the seed ; the other the needle sort, 
 investing the external tissue. In hoth cases they 
 are formed of silex, and of very simple construc- 
 tion. There are, however, many forms of spicula 
 in the great Sponge family ; and commencing with 
 the lowly form now before us, we might trace their 
 development in endless diversity, from simple needle, 
 or thornlike bodies, up to their marvellous develop- 
 ment and complexity of arrangement in the beauti- 
 ful EuplecteUa, or Yenus's flower-basket, of the 
 Manilla seas, which forms so prominent an object 
 of beauty in our own homes. 
 
XVI. NATURE'S JEWELS. 
 
 " I hold it of little matter 
 
 Whether your jewel be of pure water, 
 
 A rose-diamond or a white, 
 
 But whether it dazzle nie with light." 
 
 " Tell them, dear, that if eyes were made for seeing, 
 Then Beauty is its own excuse forl>emg." EMERSON. 
 
 A GLASS slide, on which are mounted a number 
 of Diatoms, carefully selected and artistically ar- 
 ranged, suggests the heading of this vignette. To 
 the naked eye, the whole group appears as but the 
 faintest speck on the glass. Only a relatively low 
 power enables us to see them all at one glance 
 under the microscope but this view is enough to 
 evoke the joyful acclamation, " Gems! Jewels! 
 Who would have thought it ? " We increase the 
 magnifying power, and now we can see only one 
 at a time, but by shifting the stage we bring them 
 one after another under observation ; and now a 
 
158 
 
 VIGNETTES FROM INVISIBLE LIFE. 
 
 thousand additional beauties of structure or en- 
 gravings on them are revealed. They will bear 
 any amount of amplification ; and the more they 
 are scrutinized, the more beautiful and exquisite 
 the markings are seen to be. 
 
 Gems and jewels suggest the ideas of rarity 
 
 FIG. 26.Diatonu. 
 
 and preciousness, but only the latter term applies 
 to these, for not only are they not rare, they are, 
 on the contrary, the most numerous and the most 
 widely diffused of all material objects ; and that they 
 are costly or precious can only be inferred or de- 
 clared of them when their functions, their formation, 
 and the offices they perform in the general economy 
 of nature, are understood. They are then seen to 
 
NATURE'S JEWELS. 159 
 
 be precious in a natural sense not, indeed, as we 
 speak of " precious stones," but rather as we regard 
 the prime essentials of existence even as air and 
 water, which, although so common, are yet so 
 precious that we cannot do without them. 
 
 But we are somewhat anticipating our subject, 
 for what we have hitherto spoken of are only the 
 " remains," so to speak, of the Diatoms the outer 
 covering the external skeletons the shields, 
 plates, shells, and valves, as they are respectively 
 named. And as to these, one may adopt the language 
 of Lane Clarke, and say, "As the wondering 
 astronomer discovers the infinite worlds revealed 
 in unfathomed space, and sees star after star arise 
 in countless myriads within the dim and distant 
 nebulse ; as his mind bows down overwhelmed by 
 the sense of the Omnipotent Creator's dominion 
 and guidance of all those glorious orbs: even so 
 the microscopist bends in astonished awe before 
 the infinitude of God's works in the uncountable 
 varieties and exquisite beauty of the minute 
 Diatoms." Externally the Diatom consists of two 
 plates or valves, united or kept in opposition to each 
 other by a connecting zone or rather, by two 
 
160 VIGNETTES FROM INVISIBLE LIFE. 
 
 connecting zones or girdles, which overlap each 
 other at their free extremities. These zones are of 
 great importance, as we shall presently see, and 
 therefore their structure must be clearly understood. 
 One zone would be enough if the object were 
 merely to keep the valves in position, and therefore 
 the fact of there being two is very suggestive. On 
 close examination it is seen that, although not ac- 
 tually united to the valves, yet that on one side the 
 zone is more firmly adherent to the valve with which 
 it is in contact than to the zone it overlays. This 
 overlapping sometimes gives the zones the appear- 
 ance of an intermediate valve, or the whole frustule 
 that of being a compound triplicate ; the double 
 structure, where they lie over each other, being of 
 course less transparent than on the parts imme- 
 diately in connection with the valves, on which 
 there is no overlapping. 
 
 This bivalve shell with its girdling zones 
 encloses a soft organic substance, the nature of 
 which has been the subject of much dispute. 
 Sufficient for our purpose here to say, that it is 
 generally of a bright golden yellow, which colour 
 it imparts to the external shell, and that it is the 
 
NATURE'S JEWELS. 161 
 
 seat of life, and of all the wonderful functions of 
 which the whole Diatom is the agent. Although 
 the Diatoms vary greatly in form, the structure 
 here indicated is common to all. In some forms 
 there is an additional external investment, consisting 
 of a mucous or gelatinous substance, and in which 
 they lie imbedded, side by side or end to end, in 
 filaments or chains of various patterns ; or they 
 are attached by their angles in a zig-zag manner ; 
 or aggregating in masses, they build up a fairy tree- 
 like or frondose form, or group in irregular bosses 
 around the stems of plants. Although the Diatom 
 exhibits these social tendencies in a greater or less 
 degree throughout its vast species, yet each one is 
 perfectly distinct in all that pertains to its own in- 
 dividual life, and in the majority the association is 
 only that of free companionship with its fellows. 
 
 The especial importance of the girdling zones 
 is only fully seen in connection with the propaga- 
 tion or re -production of the Diatom. Self -division 
 is the common method here, as it is also with all 
 the humble forms of life and for that matter of 
 all the higher and more complex beings, whether 
 of animal or vegetable nature the only difference 
 L 
 
162 VIGNETTES FROM INVISIBLE LIFE. 
 
 being that in the Diatoms and such like forms this 
 process affects or rather, involves their whole 
 being or individuality, whereas in complex organisms 
 it is only a process of growth, a multiplication of 
 cells from which the whole compound structure is 
 built up. 
 
 Self -division in the Diatom, however, is not the 
 simple and easy process which it is generally seen 
 to be in most other minute existences ; and for this 
 reason, that it is invested with a material that does 
 not grow pari passu with it. In other words, 
 the valves are composed of pure silex, and inca- 
 pable of participating in the process. 
 
 These two silicious valves bound the inner life 
 substance, which latter grows and expands, and 
 would undoubtedly burst its shelly investment if 
 there were no other means of overcoming its resist- 
 ance. This is furnished by the zones, which, as 
 before observed, overlap each other, apparently for 
 this very purpose ; for when the pressure of growth 
 from beneath is brought to bear against them, they 
 are able to yield to at least the extent of the overlap 
 without exposing the soft cell substance beneath. In 
 this way room is given for the living cell to grow, 
 
NATURE'S JEWELS. 163 
 
 and eventually to divide. Before this takes place 
 let us, in imagination, take another look at the 
 position of affairs. There are the valves, lifted up 
 and pushed aside, while the zones protect the new 
 formation or cell growth, on which a longitudinal 
 constriction, gradually deepening, embraces the 
 whole contents. On this, the primordial utricle 
 or membrane is being unfolded, completing the 
 division. And now on this membrane the wonder- 
 ful tracings and sculpturings, the exact pattern, or 
 rather, copy, of the parent valves, are developed. 
 The whole presently becomes silicified, and a new 
 valve is formed. The same process is of course 
 going on on the other 'side ; and when completed, 
 two Diatoms appear where only one existed before, 
 each one having an old valve on one side and a new 
 one on the other. We are watching a Diatom of 
 the linear form. The division is effected, though 
 for the moment the appearance is that of a double 
 Diatom. Presently an opening commences at the 
 forward extremities, as they move slowly along 
 together, which, gradually expanding, at length 
 terminates in final separation, and each Diatom 
 proceeds alone on its destined course. 
 L 2 
 
16* VIGNETTES FROM INVISIBLE LIFE. 
 
 There is here no decay or dissolution ; the new 
 life and the old are blended and carried forward in 
 the increased number of individuals ; and if this 
 process could be maintained ad infinitum it is evident 
 they would never die, but would fill the universe 
 with their ever-increasing numbers. 
 
 Amazing numbers are indeed produced in this 
 way, for although the process of self -fission takes 
 about twenty-four hours in each case, yet as long 
 as it lasts it proceeds in a geometrical ratio, 
 and the calculation is, that the progeny of a 
 single Diatom in one month reaches the enormous 
 number of one thousand millions of individuals. 
 But Nature imposes a limit on growth, or 
 cell-multiplication. The favouring season expires, 
 or the exhausting and resting period is reached, 
 decay supervenes, and dissolution ends the indi- 
 vidual life. Before this, however, provision has 
 been made for the recommencement of the life- 
 cycle by another process, which is not that of 
 growth or mere multiplication, but is essentially 
 reproductive. This is by conjugation, or the union 
 of the contents of two cells. Two Diatoms are 
 seen to approach each other, and after a time 
 
NATURE'S JEWELS. 165 
 
 become surrounded by a gelatinous or mucous 
 matter which holds them together. The valves 
 of each Diatom now dehisce or gape, and the 
 endochrome, or cell contents, of each flows out 
 and mingle together, forming a globular mass, 
 which gradually assumes the parental form, only 
 much larger ; or the new body thus produced may 
 assume a form unlike that of its parents. In either 
 case, however, it is only transitional in its nature 
 or rather, it is the fruit or seed whence the new 
 generation is to spring. By-and-by, it will break 
 up or open, setting free the myriad brood of embryos 
 or gonidia, i.e., spores or buds, which " either remain 
 free or surround themselves with mucous, forming 
 a pellicle or stratum, and in a definite but un- 
 ascertained period reach the mature form," when 
 they become invested with the silicious valves and 
 zones, and consequently cease to grow or enlarge, 
 except by the process of division already described. 
 Something like an alternation of generations has 
 also been observed in some varieties, one form pro- 
 ducing buds, which in their development assume 
 forms unlike their parents, and these producing yet 
 other differing ones, which in their turn reproduce 
 
ItM VIGNETTES FROM INVISIBLE LIFE. 
 
 the original. These intermediate forms having 
 been mistaken for new species, have led to over- 
 numbering the latter. There are many modifica- 
 tions of the modus operandi in both processes of 
 division and conjugation, but although of great 
 interest to the scientific student, are yet involved 
 in too much obscurity for our purpose here. 
 
 One of the most interesting features in the 
 Diatom, and one which has led to much speculation, 
 is that of its movement. It has not been observed 
 in all Diatoms, but in those in which it occurs it is 
 yery remarkable and full of interest. No loco 
 motive organs or any other agency is seen, although 
 the very highest powers of the microscope are used, 
 "yet it moves," and it is an extremely interesting 
 sight to see a number of these golden-coloured fairy- 
 like boats without oars or paddles or any other 
 visible propelling agency, gliding hither and thither 
 in slowly measured time, over the surface of the 
 miniature sea now forwards and. backwards in a 
 strictly measured and definite distance in fair 
 weather sailing, then turning, and jerking, and 
 rolling, as if an invisible storm agitated the waters. 
 In one species the movement is of the most singular 
 
NATURE'S JEWELS. 167 
 
 nature i.e., Bacillaria Paradox a, which is one of 
 the filamentous species and is found in fresh and 
 brackish water. It consists of a number of frustules, 
 i.e., Diatoms, arranged in a close sort of connection 
 
 FIG. 27. Bacillaria Paradoxa. 
 
 by some invisible medium ; and as we now look 
 at it, resembling a number of rods side by side, 
 we are reminded of the " Pan's pipes," or show- 
 man's whistle, seen in our boyhood at a country 
 fair. Scarcely, however, is the idea suggested 
 
168 VIGNETTES FROM INVISIBLE LIFE. 
 
 \ 
 than, a change in position is effected. One pipe 
 
 makes a forward movement, followed by the next, 
 and next, throughout the entire series, until an 
 almost straight and rigid rod-like form is pro- 
 duced ; then a pause, and a backward movement is 
 begun, while the hindermost is at the same time 
 moving forward, so that each half of the row is 
 moving parallel to the other in opposite directions, 
 the centre remaining stationary. Now an impedi- 
 ment is encountered and. pushed aside ; by-and-by 
 another which cannot be moved comes in the way, 
 and then the whole line of Diatoms pauses, but 
 only just so long as the forward movement would 
 have taken, and then they return. Again and 
 again is the journey attempted, and as often foiled 
 half way by this obstacle, yet there is 110 swerving, 
 no turning aside for another path, no giving up 
 the endeavour. Our patience is, however, exhausted, 
 and so we lift the thin glass cover, and with a fine 
 needle " clear the road " for our persevering 
 acquaintance. The movement is slow but regular, 
 and never did stage coach keep better time than 
 our Bacillaria Paradox a. 
 
 The cause of this, and of the movements 
 
NATURE'S JEWELS. 169 
 
 generally in the D'i atom ace ce, is somewhat of a 
 puzzle, and in this connection one is apt to ask 
 whether the beings we are observing are of animal 
 or vegetable nature ? Here there is considerable 
 diversity of opinion among the authorities, for 
 while some think that their animality is beyond 
 a doubt, others, and these the majority, are certain 
 that they belong to the vegetable kingdom ; the 
 truth probably being that they belong to both, but 
 are not absolutely one or the other. It is time 
 that naturalists recognised in popular descriptions 
 the fact, of which they are so well aware, that the 
 phrase " animal and vegetable kingdoms " is not 
 of divine authority, but purely of human invention. 
 It is well known now that there is no sharp divid- 
 ing line between animal and vegetable, where the 
 one ends and the other begins ; but that on the con- 
 trary, on this border-land the two blend into each 
 other plant -animal and animal -plant, being well 
 recognised in numerous instances, of which also the 
 Diatom is probably one. The various keen dis- 
 putes, however, have not been altogether fruitless, 
 for both parties, in order to sustain their own 
 special view, have probably brought closer obser- 
 
170 VIGNETTES FROM INVISIBLE LIFE. 
 
 vation to bear on their investigations; and have 
 thus elucidated many points of structure and 
 phases of life which might otherwise have been 
 overlooked. 
 
 Thus, on the one hand, the peculiarities of the 
 Diatom's silicious valves, which seem to be perfo- 
 rated with minute foramina, or holes, have been 
 watched with almost feverish earnestness, in order to 
 discover whether or not any filmy processes ever pro- 
 trude, which might not only account for their move- 
 ments, but go a long way to prove their animal 
 nature ; and some observers have even asserted that 
 they have seen them. Even Julias Sachs, an eminent 
 authority, who classes them (the Diatoms) among 
 the vegetable tribes, thinks it probable that it is 
 by means of such protrusion of the internal soft 
 organic matter that their creeping and crawling 
 movements are effected. On the other hand, the 
 advocates of their vegetable nature find not only 
 that the special structure and functions which the 
 other side regard as peculiarly animal are also 
 found in undisputed vegetable organisms, but also 
 that they possess other undoubted vegetable charac- 
 teristics, which are but rarely found in conjunction 
 
NATURE'S JEWELS. 171 
 
 with admittedly animal bodies, and that these im- 
 mensely preponderate over their animal or semi- 
 animal attributes. Thus, the Diatoms evolve oxy- 
 gen, rise to the surface of the water in sunlight, 
 and in the Antarctic Ocean (as we are informed 
 by Dr. Hooker) their vegetable nature is of such 
 importance that but for them the water, in the 
 utter absence of other vegetables, could not be 
 purified from the carbonic acid caused by animal 
 respiration and decomposition, and that thus by 
 their immense numbers they not only furnish 
 an abundance of vegetable food to the herbivor- 
 ous mollusca, and other inhabitants of the sea, 
 but that without them the balance of nature would 
 be so disturbed as to render the continuance of 
 animal life impossible in those regions. Yet they 
 exist in equal, or even in greater abundance, in 
 tropical seas. Dr. Wallich found them, with but 
 little interruption, to the depth of some feet 
 throughout six degrees of longitude in the Indian 
 Ocean, and there they were of such gigantic size as 
 even to be visible individually to the naked eye. 
 Thus the argument for their vegetable nature has 
 a twofold aspect ; for if vegetable, by analogy we 
 
172 VIGNETTES FROM INVISIBLE LIFE. 
 
 should expect their growth to be greater and more 
 brilliant in the tropics which is the case ; while in 
 the polar regions their peculiar structure fits them 
 to supply the place of other vegetable life, and 
 makes them of prime importance as an article of 
 food, and natural equilibriating agency. Still, if 
 wholly vegetable, one would hardly expect to find 
 them so abundant under conditions so unfavour- 
 able to vegetation as the Antarctic Ocean. 
 
 What we become actually aware of in this dis- 
 cussion is the fact of their immense importance in 
 the order of nature, for which their peculiar com- 
 bination of both animal and vegetable nature ren- 
 ders them the unique agents they are. 
 
 We might go further, and say that the Diatom 
 is not only a combination of animal and vegetable 
 nature, but that it represents in its structure the 
 mineral kingdom also ; for are not its valves com- 
 posed of silex, or flint, which it can only obtain 
 from the mineral kingdom, and which constitutes 
 the greater part of its bulk, if such a word may be 
 applied to such minute existences. 
 
 In the reproductive process the germs of future 
 generations being secured, the parental cells die, 
 
NATURE'S JEWELS. 173 
 
 and their almost indestructible coverings fall to the 
 bottom of the water, forming in many cases vast 
 deposits on the floor of the ocean, the mouths of 
 rivers, and the beds of fresh water lakes, &c. Or 
 the living Diatoms are devoured by fishes, and 
 these in their turn by birds ; and though thus sub- 
 ject to a double digestive process, their silicious 
 valves turn up again in guano, and when cleaned 
 and mounted are objects of great beauty. Indeed 
 it is the casket, and not the priceless life gem it 
 contains, which has attracted most attention to the 
 Diatom ; and this is not to be wondered at, or even 
 deplored, when its varied and beautiful form and 
 exquisite sculpturing are considered. 
 
 Variety is a general law in all kinds of life, but 
 in many of its lowly forms (as we have seen) this 
 is characterised by great irregularity. The reverse 
 is the case in the Diatomacea, where symmetry 
 is the universal law the valves and the engrav- 
 ings on them being formed with mathematical 
 accuracy, and matchless artistic delicacy and skill. 
 Any attempt, however, at verbal description not 
 only cannot do justice to this part of our sub- 
 ject, but would rather damage it than otherwise. 
 
174 VIGNETTES FROM INVISIBLE LIFE. 
 
 So, in the absence of elaborate and expensive 
 drawings, we can only say to the reader, examine 
 them for yourself ; put them under the most 
 searching gaze, and with the highest powers of 
 the microscope, and the more you scrutinise, the 
 more beauty will be revealed, and the greater will 
 be your wonder and admiration. 
 
 Other gems and jewels rare, will fade into in- 
 feriority beside these productions of nature. The 
 midnight lamp grows dim as the hours pass by 
 and your whole being is rapt in adoring con- 
 templation. The dull earth is transformed, not 
 in imagination only, but in sober truth to your 
 mind, for is it not really encrusted all over with 
 these sparkling gems, far surpassing all the 
 dreams of magician or poet ? 
 
 One hundred millions of Diatom caskets do not 
 weigh a grain. A single cubic inch of the polish- 
 ing slate in Bohemia, which exists in beds or strata 
 of fourteen feet in thickness, contains forty thou- 
 sand millions of them. Vast and extensive tracts of 
 the earth's crust is formed almost entirely of them. 
 The city of Richmond, in Virginia, is built on a 
 bed of Diatomacece eighteen feet in thickness. 
 
NATURE'S JEWELS. 175 
 
 They stand the wear and tear of the elements 
 for thousands of years. They are found in pumice- 
 stone, and in the ashes of both active and extinct 
 volcanoes, in meteoric dust, in the stomachs of 
 fishes and birds, in the deepest recesses of the 
 ocean, in the pancake ice of the polar regions, amid 
 the mangrove swamps of the tropics, on the moun- 
 tain tops, and in the valleys beneath. Earth, air, 
 and water every clime and country on the globe- 
 are penetrated by Diatoms, either fossil or living, 
 or both. 
 
 Diatoms in their living state constitute a kind 
 of almost universal food ; from the humblest infu- 
 sorian up to man himself, all partake of them in 
 one form or another ; and even their silicious re- 
 mains, mixed and baked with common earth, are 
 sometimes the food of starving man ; while the 
 Japanese make a delicate and nutritious soup with 
 them in their living condition, along with certain 
 kinds of sea-weed. They also add greatly to the fer- 
 tility of the soil, while at the same time increasing 
 its quantity. It is well known that the best guano is 
 that in which Diatoms are most abundant, and that 
 river deposits rich in diatomaceous remains are very 
 
176 VIGNETTES FROM INVISIBLE LIFE. 
 
 valuable as fertilising agencies. In the arts and 
 manufactures they are brought into use as polish- 
 ing powder, as the finest material for delicate 
 metallic castings ; and in the manufacture of porce- 
 lain they are invaluable. 
 
 As indicating the value and importance of the 
 DiatomacecB from a natural standpoint, or the value set 
 upon these, her favourite jewels, by Dame Nature, w r e 
 may mention the singular fact, that although found 
 in a fossil condition in connection with the dawn of 
 life on the globe, yet, in the words of Dr. Gregory, 
 " We have no evidence that any species of Diatom 
 has become extinct, as so many species, and even 
 genera and tribes, of more highly organised beings 
 have done." It is not pretended by these remarks 
 that no new species have been produced, the reverse 
 being well known, no form of life exhibiting greater 
 varieties but only as indicating their importance 
 in that, through all the mutations of other forms 
 of life, while they come and go, the Diatom, though 
 evolving an almost infinite variety through thou- 
 sands or millions of years, has been preserved, in all 
 its original specific characters to the present time. 
 
 The multitudinous variety of figure and sculp- 
 
NATURE'S JEWELS. Ill 
 
 turing in the Diatoms are beyond description, yet 
 they all exist under a few general characteristic 
 forms. Thus they are attached to each other by a 
 stalk or pedicle, or coherent in chains and branching 
 tufts, or isolated and free ; and under these several 
 forms or conditions of existence they assume an 
 endless diversity of figure and markings, which to 
 describe in detail far surpasses our skill. A few 
 words strung together may, however, give some 
 general idea of these diversities. 
 
 Thus as to their figures : they are wand-like, 
 trapezoid, square, round, circular or like a pill-box, 
 globular or spheroid, boat-shaped, oval, egg-shaped 
 or ovoid, discoid, wedge-shaped, cuneate, triangular, 
 rectangular, curved, twisted, sigmoid or undulate, 
 arcuate, saddle-shaped, geniculate, alate or winged, 
 lunate, &c., &c., &c. 
 
 Then as to the symmetrical designs or mark- 
 ings on the valves, some are hexagonal, others are 
 marked in lines of round or oval dots. The mark- 
 ings on the discoid forms are generally the most 
 beautiful, and in some the pattern is divided into 
 six, eight, or ten compartments, all arranged round 
 a common centre, and beautifully ornamented with 
 
 31 
 
178 VIGNETTES FROM INVISIBLE LIFE. 
 
 the finest and most delicate precision. In one i.e., 
 AracJuioidiscus Japonicus, in which the valves are of 
 a double nature, the external being horny, and the 
 internal silicious the markings on the external 
 valve are after the pattern of the spider's web 
 (hence its name), and on the internal, like that 
 of a " circular Gothic window," both together 
 forming a remarkable design, executed with mar- 
 vellous delicacy and mathematical exactness. 
 
 Then there are the beautiful Coscinodisccce, with 
 numerous genera and species, not divided into com- 
 partments. In one species (C. ocnlus) the valves 
 are marked with hexagonal areola? or circles, in the 
 centre of which appears a peculiar eye-like forma- 
 tion. Of other discoidal forms, such as Calodiscus, 
 Campylodiscus, Cr asp edo discus, Eupodiscus, Hemi- 
 discus, Hyalodiscus,0dontodiscus, Pododiscus, Stephan- 
 odiscus, with their numerous species and varieties, 
 as well as the immense number of other forms 
 into which the vast realm of the Diatomaceae are 
 divided, we must forbear to speak further. The 
 subject is too vast for such a little work as this, 
 which aims only at awakening an interest in 
 invisible life, and of indicating where or in what 
 direction it may be gratified. 
 
CONCLUSION. 
 
 " Once lieave the ball from the hand, and oiie cau show how all 
 this mighty order grew. That famous aboriginal push is propa- 
 gated through every atom, through all the races of creatures, and 
 through the history and performances of every individual." 
 EMERSON. 
 
 THE word invisible, as applied to at least some of 
 the forms of life here treated of, and notably to the 
 Sponge, may appear to an objector as a misnomer. 
 Yet, not to be hypercritical, he might say : "I 
 understand that by this term you mean those forms 
 of life which are invisible, or nearly so, to the un- 
 assisted eye, and though not literally correct, yet 
 is sufficiently so for our ordinary every-day-life 
 mode of speaking, in which considerable latitude 
 of expression is allowed, and no misunderstanding 
 results. But to speak of a Sponge, which can be 
 readily seen, as belonging to this class of being is 
 surely erroneous/' 
 
180 VIGNETTES FfiOM fNVTSIVLE LTFE. 
 
 V 
 
 To answer such an objection one might at first 
 admit the imputation, and be in harmony with the 
 general impression on this subject. But we prefer, 
 on the contrary and this for a special purpose to 
 go behind the objection in order to answer it, and 
 in so doing to ask the very old and oft -repeated 
 question, not " What is invisible life ? " but " What 
 is life?" for it seems necessary to have some 
 notion of the thing itself before saying anything of 
 its qualities. Should we be surprised if told that 
 all life is invisible ? That, however, seems to be 
 the case, though, of course, it was not with this idea 
 that these sketches were commenced, or in this 
 sense that they were named " Invisible Life." The 
 Sponge before alluded to affords a good illustration 
 of the idea here sought to be conveyed ; and whether 
 happily or not, it has been the immediate agent in 
 suggesting it in this connection. In the Sponge we 
 see with our naked eye almost as much as with the 
 microscope, so far as its exterior is concerned, yet 
 no sign of life appears. There is the dull, opaque, 
 immobile mass of matter, but no visible action no 
 locomotion ; not even is any organisation visible. 
 The mystery of its being, its living activities, are 
 
CONCLUSION. 181 
 
 all hidden beneath that very visible exterior ; and 
 in this sense there is no mistake in classing our 
 Sponge life with the invisible. Still, this illus- 
 tration, so far, is only an approximation to our 
 idea. To make the matter plainer, let us say 
 that although we are daily looking on natural 
 objects, or rather on living forms, as bird, beast, 
 flower, and tree, yet that in reality we see only 
 the external forms, underneath which the real life 
 is hidden. We perceive the organised structure, 
 but not the living matter the product, but not 
 the agent. 
 
 Cutting, or tearing open the Sponge, we can, as 
 previously described, by the aid of the microscope, 
 and that alone, see the otherwise invisible agents, or 
 the living forces, the nearest approach to actual 
 living matter, which in its essential purity is with- 
 out any structure or organisation whatever. This 
 Amoeboid matter, or protoplasm, is then the hidden 
 basis of life, animal and vegetable, the invisible 
 agent of all organisation. It is a singular fact 
 that this living matter cannot be analysed, for 
 the instant this is attempted its essential quality, 
 that which is its prime element, eludes our grasp : 
 
lSt> 7IQNETT$8 FROM INVISIBLE LIFE. 
 
 the life has fled, and our analysis may indeed pro- 
 ceed, but the result will be that of dead, not living 
 material. 
 
 The chemist may snve us the constituent 
 
 / O 
 
 elements of this dead matter, may possibly though 
 as yet he has not done it reproduce it in his 
 laboratory by methods not ordinarily employed 
 by nature, yet the living element, the one thing 
 needful, will be lacking, and he will be as far 
 off as ever from the unapproachable cause : the 
 absolutely invisible life of the universe, " whom no 
 man hath seen or can see," but " in whom we all 
 live and move and have our being," in whom centres 
 all our confidence, all our joy in the present, and 
 hopes in the future. 
 
 Finally, the author would have his work read in 
 the spirit in which it is written, which cries, " Give 
 me truths, for I am weary of the surfaces," in the 
 spirit of the men of old : preferring things to names. 
 The prevailing spirit of the present time is that 
 of gairiy and which, when applied to the study of 
 nature, results in a reproduction of the "apples 
 of Sodom " beautiful in appearance, but yielding 
 only bitterness and dust, when appropriated by 
 
CONCLUSION. 183 
 
 its votary. This blighting experience is very 
 happily expressed by Emerson, thus : 
 
 " Our eyes 
 
 Are armed, but we are strangers to the stars, 
 And strangers to the mystic beast and bird, 
 And strangers to the plant and to the mine. 
 The injured elements say ' Not in us ; ' 
 And night and day, ocean and continent, 
 Fire, plant, and mineral, say ' Not in us,' 
 And haughtily return us stare for stare ; 
 For we invade them impiously for gain ; 
 We devastate them unreligiously, 
 And coldly ask their pottage, not their love. 
 Therefore they shove us from them, yield to us 
 Only what to our griping toil is due. 
 But the sweet affluence of love and song, 
 The rich results of the divine contents 
 Of man and earth, of world, and loved and lover, 
 The nectar and ambrosia, are withheld ; 
 And in the midst of spoils and slaves, we thieves 
 And pirates of the universe, shut out 
 Daily to a more thin and outward rind, 
 Turn pale and starve." 
 
 THE END. 
 
 CASSELL & COMPANY, LIMITED, BELLE SAUVAUK WOKKS, LOMOX, E.G. 
 
State House Book Shop. 
 
 Newman F. McGirr 
 22 IS. 5th St., PhiJad'a.