Protoplasmic theory of life

Front matter

FRC.

K L E I N T I BOOK S

397 Bedford i

Preface

THE subject of this work was the theme of an inaugural address to the Microscopical Society of Liverpool, delivered by me as President for the year 1874. My attention had been directed to the subject for several years, and materials accumulated for the treatment of it far beyond what could be given in the compass of a lecture. These materials have been, to some extent, used in the Second Part, and the rest were intended for the Third Part of " Life, and the Equivalence of Force," a work in which I have endeavoured to bring before the notice of biologists the remarkable anticipation of certain recent views on the nature of life and other physiological questions, contained in the, partly posthumous, works of Dr. John Fletcher, of which I am the sole surviving editor. It has seemed, however, better to publish what refers to this subject complete in itself, leaving my hands free for other matters, especially the stimuli : hence the present book. As no claim to original discoveries is here put forward,

IV PREFACE.

I have preferred giving extracts or full analyses of the writings of the original observers to whom the building up of the Protoplasm theory is due, rather than writing a compendium which would most probably fail to give so accurate or interesting an account of them. Also, as this work is addressed to men of general culture in science rather than to those technically educated, I have entered on the general physiology of some parts of the subject more fully than would be required by the latter. But by these means it is hoped that men of general scientific culture may have the opportunity at hand of judging of the important theory attempted, however imperfectly, to be set forth in this book, viz., that every action properly called vital, throughout the vegetable and animal kingdoms, results solely from the changes occurring in a structureless, semifluid, nitrogenous matter now called Protoplasm.

LIVERPOOL, October, 1874,

Chapter I

The Two Chief Theories of Life stated, 1 ; Fletcher's Fundamental Principles, 3 ; Vitality the Property of Matter in a State sui generis, 5 ; only One Anatomical Element Exists in this State, 8 ; Stimuli Essential to Vital Action, 11.

Chapter II

Cell Theory before 1860, 13 ; Schleiden and Schwann, 14 ; Goodsir, 16 ; Leydig, Max Schultze, Hackel, 19 ; Virchow, 20 ; Cell Theory Goes Against the Anima-Theory, 21 ; Cell Theory Defective, 23.

Chapter III

Protoplasmic Theory before I860. 24 ; Schwann, 25 ; Dujardin's Sarcode, 26 ; Schleiden's Cytoblastema, 27 ; Von Mohl's Protoplasma, 29 ; Naegeli, 31 ; Alexander Braun, 33 ; Cohn, 35 ; Pringsheim, 36 ; Huxley, 37 ; Summary, 38.

Chapter IV

Beale's Protoplasmic Theory in 1860, 40 ; Separation of Living from Dead Matter, 44 ; Note on the word Protoplasm, 45 ; Vital Properties of Protoplasm, 47 ; Protoplasmic Movements, 49 ; Chemical State of Protoplasm, 53 ; Physical State of Protoplasm, 55 ; Relation of Protoplasmic and Cell Theory, 57 ; Beale on the Nucleus, 59 ; the Carmine Process, 61 ; Proofs of Beale's Theory, 66.

VI CONTENTS.

Chapter V

Process of Nutrition solely Vital, 70 ; Secretion also Results from Death of Bioplasm, 72 ; Specific Kinds of Protoplasm, 75 ; Fletcher's Dilemma, 76 ; Difficulties of the Protoplasmic Theory, 78 ; By-products are always formed in Secretion, 80 ; By-products of Bacterial Life, 81 ; Absorption, 82 ; Regressive Metamorphosis, 87 ; Absorption a Metainorphic Process, 89 ; Bone Absorption, 90 ; Blood Formation, 91 ; Bioplasts of Capillaries, 94.

Chapter VI

Cell and Protoplasm History since I860, 96 ; Max Schultze, 97 ; Haekel, 100 ; Briicke, Lockhart Clarke, 102 ; Strieker, Ranke, Van Beneden, on the Nucleus, 103 ; Cell Theory virtually given up, though nominally held, 104 ; Theory of One Sole Living Matter not generally Adopted, 105 ; Bastian and Cleland's Objections, 106.

Chapter VII

Commentary on Beale's Nerve Theory, 109 ; Kinds of Nerve Fibres, 111 ; No Nerve Ends, 113 ; Extreme Subdivision of Nerve Fibrils, 115 ; Nerve Centres, 116 ; Protoplasm the Only Living Part of Nerves, 119 ; Nerve Action not Mere Conduction, 121 ; Nerve Force probably of One Kind only, 123; Trophic Nerve Influence denied by Beale, probably erroneously, 124 ; Nature of the Nerve Current, 126 ; Arguments for and against its being Electricity, 127*

Chapter VIII

Commentary on Beale's Muscle Theory, 130 ; Beale's Anatomy of the Fibre, 131 ; it does not contain Protoplasm, 132-3 ; All Muscles contain Nerves which evolve the Force, 134 ; Schiff and Kiihne on Idio-Muscular and N euro-Muscular Irritability, 136 ; Kuhne's Nerveless Zones, 136 ; Chemical Irritants said to prove Idio-muscular Irritability, 138 ; Galvanism said to furnish the Force for Contraction, 140 ; Various Authors on the Histology of the Fibre, 141 : Analogy of Muscular with Electro Magnetic Action, 144 ; Muscle

CONTENTS. vii

Force incomparably greater than that of the Nerve Stimulus, 145 ; Sources of Work immediately Albuminous, although ultimately Non-Nitrogenous, 146 ; Chemical Changes in Living Muscles, 147 ; Storing of Oxygen, 149 ; Compensatory Processes to prevent Waste of Nitrogen, 151 ; Intra-muscular Nerve Protoplasm the Source of the whole Muscle Force, 155 ; Proofs of its Sufficient Quantity, 156 ; Tongue of Chameleon, 158 ; Intermediate Chemical Force-evolver formed by the Protoplasm, 159 ; Animal Electricity, 161 ; Negative Variation accompanies Nerve Action and Animal and Vegetable Contractions, 162 ; Electricity a Stimulus, 164 ; Cannot be Nerve Force, as it is wasted by Bad Conduction, 166; Nerve Force ^probably a Specific Current Force, 167 ; Muscle-work Inductive, 168 ; Stimulus both Direct and Derived, 169 ; Conclusion in Favour of Beale's Theory that Muscular Contraction is a Physical Act, 171,

Chapter IX

Nature of Life, 174 ; Fletcher's and Author's Definitions, 175 ; H. Spencer, Lewes, and De Blainville, 176 ; Both Vital and Non-vital Elements in all Functions, 177 ; Molecular Complexity probably the Cause of Vitality, 180 ; Metabolic instead of Vito-Chemical, 182 ; Physiological Units same as Fletcher's Irritable Matter U83 ; Madden's Complexity Series, 186 ; Compound Nature of the Elements, 187 ; Elementary, Chemical, and Metabolic States of Matter, 1 88 ; Physical State of Protoplasm, 191 ; Molecular Organization of Protoplasm, 195 ; Dynamic State of Matter, 196 ; Chemical and Metabolic Action not Mutual, 198 ; Stimuli, 199 ; No Spontaneity in Living Matter, 200.

Chapter X

Connection of Force with Life and Mind. . Force an Affection of Matter, 205 ; Definitions of Force, 207 ; Challis's Hydro- Dynamic Theory, 209 ; Force nothing but MV2, 210 ; Distinction between Property and Force, 212 ; Secondary Properties imply Presence of Force, 214 ; Force has no Determining Power, 216 ; Beale's Vital Power, 218 ; No

Vlll CONTENTS.

such thing as Vital Force, 221 ; Revival of the Vital Principle as Force, 223 ; Misuse of the word Force, 224 ; Where Beale and Fletcher differ, 226 ; Consciousness and Force have no Mechanical Equivalence, 230 ; Consciousness an Incidental Phenomenon, 234 ; Thought a Function of Matter, 235 ; Will cannot create Force, 238 ; Physiological Materialism, 240 ; Spirit Inconceivable to us, 242 ; Bain and Lewes on Consciousness controverted, 244.

CHAPTER XL

Albumen and the Physical Basis of Life, 247 ; Huxley's Language misunderstood, 248 ; but it was ambiguous, 249 ; Aquosity Argument, 251 ; Hack el's Ambiguity traced to his Pantheism, 253 ; HackePs Divine Spirit in Matter, 255 ; Archigony, 256 ; Plasmagony, 257 ; Herbert Spencer's Autogony, 259 ; Butyrate of Dimethylamin from Inorganic Materials, 258 ; Spontaneous Generation of Bacteria not proved, 263.

Chapter XII

On So-called Materialism, 265 ; HackePs Materialism, 266 ; Huxley's Evasion of the Question, 267 ; Fletcher's Materialism as to Life and Mind, 268 ; Fletcher's Distinction of Mind from the Immortal Soul, 269 ; Natural Theology no Science, 273 ; it lends no Support to Religion, 277 ; Samuel Brown on the failure of the Argument from Design, 281 ; Science to Sight, Religion to Faith, 288.

THE PROTOPLASMIC THEORY OF LIFE.

Chapter I. Introduction, And Fletcher's Theory Of One Only Living Matter

WERE it possible even to do so in less than a volume, it would be tedious and' unprofitable to go over the history of all the theories of life, so I will begin at the point where it became clearly apparent that all the varieties of opinion might be summed up under two heads —

1. Those which require the addition to ordinary matter of an immaterial or spiritual essence, substance, or power, general or local, whose presence is the efficient cause of life ; and

2. Those which attribute the phenomena of life solely to the mode of combination of the ordinary material elements of which the organism is composed without the addition of any such immaterial essence, power, or force.

Up to the year 1835, the balance had been inclining against the hypothesis of a vital principle, at least in the crude form hitherto predominant, but the minds of physiologists were far from clear, and the ideas of some central vital influence, which ruled over all local actions, or even furnished vital influence to them, were still in the ascendant.

In 1835, Joh. Muller commenced an essay on " Organism and Life " with the following words of Kant : " The cause of the particular mode of existence of each part of a living body resides in the whole, while in dead masses each part contains the cause within itself."* The sense in which this was taken is, that some central power or influence in each individual, presided over the formation, nutrition, and vital action of all parts, and correlated them into an harmonious whole, and, in fact, furnished vital influence or power to the separate parts. This is just what the vital principle was assumed to effect in olden times, and, in fact, to ascribe a power of this nature to any, even material parts, such as a central nervous system, under the name of "vital force and power," or "directing agency," or " directing power," is nothing better than the old vital principle with a new name.

We see, thus, in the above-mentioned work, the author, then the highest authority in Germany, and, .at the same time, an original observer, has, as it were, his face still directed backwards to the old theory of a spirit, or, at least, central power of some kind animating each living individual, and, with the help of the material organs, performing the functions of life. Such a work soon belongs to the past.

In the same year appeared another work on physi-

* Strieker, Syd. Soc., vol. xlvii. p. 1.

ology by an author whose face was directed to the future, and who, abandoning all the ancient theories of spiritual essences as the efficient causes of vital phenomena, referred these latter solely to the inherent properties of the elementary parts, and thus placed himself in harmony with the philosophy of the future.

In this year, 1835, in his masterly work, " Rudiments of Physiology," Dr. Fletcher, of Edinburgh, systematically reviewed, for the last time, the old hypothesis of a vital spirit, or essence, or principle, as the cause of life, and gave it, we may suppose, the coup de grace, for the question is seldom argued now in physiological works, and it is the fashion to treat it as an exploded theory, even by those who have not clearly apprehended the alternative, and are really still following it under other names. That alternative was, however, clearly apprehended by Fletcher, and with such force that he was impelled by the mere course of consistent reasoning to frame an hypothesis of the anatomical nature of the living matter which anticipates, in a remarkable manner, the discovery of the protoplasmic theory of life, which is our subject here. The two chief points laid down by him are —

1. That if vitality do not reside in a separate principle, but depends upon the mode of combination of the elements of the organic parts themselves, there •can be no central vital influence communicable to the parts and dominating them, for the vitality of each must be inherent in itself, and, as a property of the material compound, cannot be transferred to the smallest distance ; each part, organ, arid even cell, there-

1—2 fore, possesses a quasi-independent life, and they are all bound together to form an individual merely by the ties of a central nervous system and common circulation or some similar means when these are not present. This is not taught as anything original, and it was a view more or less distinctly expressed by the older physiologists, e.g., Fallopius.

2. That the property of vitality does not reside equally in the various organic structures requiring such different physical properties, but is restricted solely to a universally-diffused, pulpy, structureless matter, similar to that of the ganglionic nerves and to the gray matter of the cerebro-spinal nervous system. This is, as far as I am aware, a perfectly original hypothesis.

No doubt it is easy enough to perceive that the invocation of a spiritual principle which shall cause common, chemically-combined matter to display the powers of life, as an explanation, is no more philosophical than to believe in the capacity of such agencies as witchcraft and magic to do work without adequate physical power. But when we come to particulars, and ask the physiologist who asserts that vitality is merely the property oj.a certain chemical combination of matter just asKquosrtlv is the property of the chemical compound we call water, how it comes that from no known chemical action or process can we obtain results the least like living action, he is at fault. He can name and define by chemical tests the matter after death, which a moment before was living, but he cannot now perform a single vital function with this very matter presumed to be identical, and if he does not fall back upon the notion of some essence or principle which escaped at death, leaving the chemical compound the same, he speaks with extreme vagueness of a peculiar variety of force called vital, evolved from the chemical force of the food by subtle chemical processes which we cannot as yet imitate in the laboratory. It is easy to show that no possible form of iorce, as defined in physics, could compel chemical compounds, such as albumen, fibrin, and others presumedly making up the living matter, to act differently from the manner in which they must act according to their molecular composition, as albumen, protein, and the rest.

The difficulty was felt and acknowledged by Fletcher, and instead of evading it, he met it at once, and declared that the truly living matter was not in simply a somewhat different chemical state from that in which it exists after death — such a statement would be a mere bald truism — but that the elements are in a state of combination not to be called chemical at all in the ordinary sense, but one which is utterly sui generis. That, in fact, no albumen, fibrin, myosin, protagon, or fats exist at all in_the_living_ matter, but that the sum of the elements of all these is united into a compound, for which we have no chemical name, and of the complex mode in which the atoms are combined we can form no idea ; and it is only at the moment of death that those chemical compounds, with which we are familiar, take their origin. In fact, that death means simply the resolution of this complex combination into the simpler compounds, albumen, fibrin, and the rest, which we find on analysis. Among the expressions of Fletcher on this point, I may quote the following :

" It is only at the instant of the cessation of tho vitality of each organized tissue that these compounds or reputed proximate principles are formed — at that instant when the power called chemical affinity succeeds another power which may be called vital affinity^, and by which it had been previously superseded, and common chemical compounds are all that is left of that organized mass into which the elements had been associated." Nor is this " power called vital affinity " any essence or force added to the living matter, for "irritability or vitality is a property of organized or living matter, as characteristic of this as inflammability of phosphorus, or elasticity is of ivory." Again : " The process of secretion, by which the ultimate ingredients of all vegetable and animal compounds, whatever they may be, are brought together, is perhaps an infinitely more subtle and searching power than that of common chemical affinity." Nevertheless, it is not anything foreign to the properties of matter, for he adds, "Secretion is a process, although not identical with, still analogous to, common chemical affinity."*

With such sharply defined distinctions between the chemical and vital state of combination of the atoms

* The clear expressions of Fletcher gave no countenance to any ambiguity respecting the nature of his living or "irritable matter, !> such as has lately been experienced respecting protoplasm by the application of that word both to living and dead matter. "Chemical analysis accordingly must be considered as useful in showing us, not what such matter was composed of while it possessed vitality, but what it is composed of afterwards " (135). And, he adds in a note, "The grave-digger, in Hamlet, spoke more ' by the rule' in these matters — * One that was a woman,' says he, ' but, rest her soiil, she is dead.' "

of matter, as might be expected Fletcher gives no countenance to the idea of any intermediate stage between them — any stage, as it were, common to both which would permit the gradation of one into the other. There, is no such thing as vito-chemical in the sense of partaking of both states. On the contrary, the division is sharp, abrupt, and absolute, and between them is an unfathomable gulf.

Vitality is thus a property inherent in each particle of the living matter, and as all the parts of a complex organism differ in function, each part has a specific kind of vitality peculiar to itself. An individual of any species is thus a complex congeries of a number of subordinate quasi-independent living units,, whose life is complete in themselves. It is impossible even to touch upon the large question of the development of the germ into the harmonious arrangement of different organs and parts in perfect adaptation to their purpose, but it may be stated that in the absence of any central, overruling, semi-rational, vital principle, Fletcher holds "that the development of those parts is immediately effected by certain inherent powers, of a different nature indeed, but not less definite in their operation than those which determine the crystalization of a mineral " (i. 65).

With respect to the second proposition, that this peculiar property of vitality does not reside in the tissues indiscriminately, but in one anatomical element alone, it is sufficiently obvious that as the various tissues differ extremely in their physical properties, and these latter are almost exactly the same after as before death, it is hardly to be expected that the living matter can die into or rearrange itself in a short time into a number of different forms, which shall possess exactly the same physical properties in the vital as in the ordinary state of combination. It is likewise to be expected that as the vital or metabolic molecular changes in the living matter must be very rapid and complicated, the physical state of it cannot be hard or rigid, and this agrees with what has been long known of the parts in which life is most active and intense, viz., the gra}T matter of the nervous system. Moreover, we know that there is no example of life existing in any gaseous or purely liquid fluid. These considerations narrow the probable field of the seat of vitality very much, and the following question thereupon is raised by Fletcher : — " Admitting that irritability or vitality, general and specific, is a property of the organized solids alone, it becomes a question of the highest interest whether it be directly inherent in each of the organized tissues, either of plants or animals, or whether it merely appears to be possessed by them all in virtue of -some one which is universally distributed over the organized being, and inextricably interwoven with every other " (ii. p. 55). He examines this question, and by an interesting train of reasoning, based chiefly on arguments derived from comparative anatomy and physiology, he comes to the conclusion that vitality is not inherent in any liquid, nor in any of the rigid structures, and that it is only in virtue of a specially living matter, •universally diffused and intimately interwoven with its texture, that any tissue or part possesses vitality. Therefore, he " must deny any direct participation in irritability or vitality to those peculiar aggregations of matter which go to form respectively the cellular, dermoid, mucous, serous, vascular, fibrous, osseous, cartilaginous, or muscular tissues," and also to the white matter of the nerves. Thus every one of the structures possessing any degree of rigidity, usually denominated the living tissues, is in reality dead just as much as cuticle, hair, nails, and all the pure fluids.

.The only truly living matter consists of the gray^l matter of the ganglionie nerves, which he held to be ^ universally diffused, and the gray matter of the brain / and spinal marrow.

The physical and chemical description of this one true and only living matter is that of " a pulpy, translucent, homogeneous matter, yielding, after death, fibrin." Thus we have the remarkable conclusion

/that all that is properly called structure and gives form and beauty and fitness for purpose to animals

I and plants is dead, and composed of merely chemically combined elements, just as we find it after death. Here then is an ample field for the display of those mechanical and chemical actions, which are certainly largely represented in the functions of living beings, without trenching on the truly vital actions. We may, without difficulty, now perceive how the bones give firmness and support ; how the teeth grind the hardest substances ; how the arteries and veins form a perfect system of conduits for nutrient fluid ; how the fibrous, elastic, and connective tissues perform their respective physical functions; how the muscles form an apparatus, admirably adapted for the physical conditions of motion in a particular direction, while a purely vital process may be concerned in the perception of the stimulus and transformation of the needful force ; how osmosis, chemical fermentation, interchange of oxygen and carbonic acid by the haemoglobin, and all the various processes, strictly chemical and physical of animals and plants, are performed in harmony with vital actions, properly so-called. These last, residing in this "nitrogenous, pulpy, translucent, homogeneous matter, yielding, after death, fibrin," and which is everywhere interwoven with the tissues according to the degree to which they can be called living tissues, of course, must vary in strict dependence on the changes in quantity and quality of this marvellous combination of matter — so utterly unlike ordinary chemical compounds, and which alone possesses the faculty of growth or self-renewal and increase from heterogeneous matter. I With every vital action, including formation and absorption of tissue and secretions, assimilation, respiration; generation ; with every evolution of force ; with every sensation, thought, and act of volition, some portion of this wonderful substance must pass from the vital down to the chemical state — must be consumed, in fact — and a corresponding quantity of new living matter assimilated from the pabulum.

The process of assimilation, lie held, was always truly vital, and the components of the tissues were never absorbed and merely deposited unchanged from the nutrient fluid, but were always, however near in composition, decomposed, and their elements rearranged in the process ; and so marvellous is the power of the living matter in analysis and in producing new syntheses, that he thinks reasons are not wanting to lead us to suppose that it may resolve and transmute the so-called simple elements themselves.

The intimate dependence of every phase of vital action, and of the different properties of the living matter, throughout the whole range of animals and plants, on a corresponding change of molecular composition of the living matter, made up as it is of the same few ultimate elements, cannot as yet be demonstrated experimentally, because finer analyses of the products of different varieties of living matter, after death, are still wanting owing to the difficulty of its isolation > and also, because this, no doubt, mayj consist in the mere arrangement of the atoms in the extraordinarily complex molecules of the living matter, as we see in ordinary chemistry with the various series of isomeric bodies.

Not only is every vital action traced to molecular change and to consumption and regeneration of this structureless, semi-fluid matter, combined in a way entirely sui generis, but the initiation of these changes is brought by Fletcher into absolute dependence on < stimuli, and all spontaneity or autonomy is denied to * matter in the living just as in the dead state. Thus every physiological action is reduced to dependence on adequate causes exactly in the same way as the phe- ? nomena of the inorganic world. The necessity for stimuli to all muscular motion, and to the senses, and to many secretions, is generally recognized, but that they are equally essential for growth, develop-

12 PRdTOPLASMIC THEORY OF LIFE.

ment, and nutrition, is overlooked by many physiologists, who still speak of certain actions and functions as spontaneous, and as thereby manifesting a distinction between the organic and inorganic kingdoms of nature.

Chapter II. Cell Theory Before 1860

THE progress of physiological knowledge from the time of Fletcher may be said to be bound up in the history of the cellular theory, which may be considered practically to have begun in 1838, when the microscope was sufficiently perfected to give a solid basis for the observation of facts. The hypothetical anticipation of it by various authors in preceding times, although interesting, need not detain us, and I may merely refer those desirous of studying it to Professor James Tyson's excellent work on the cell doctrine. Taking up the subject from 1838, I will endeavour to select from the bewildering mass of details and conflicting statements which have accumulated since then those points which have a definite bearing on the principles of the question. This may be best done by tracing the cell doctrine in its complete form up to the time when the cell was generally accepted as the ultimate elementary unit of life; then, by tracing again from the beginning the doctrine which is believed by many to have now supplanted it, viz., that the place of the cell is to be taken by one of its constituents — the protoplasm.

14 CELL THEORY BEFORE 1860.

This may be given up to the period of its full development by Dr. Lionel Beale, and after that a review of the present state of knowledge upon these, in some respects, rival theories. This method will, I think, conduce to clearness of understanding the subject, better than the strictly chronological method in which both are mingled together.

Schleiden, who was the founder of the cell theory, though by him restricted to plants, defines the vegetable cell as " the elementary organ which constitutes the sole essential form-element of all plants, and without which a plant cannot exist ; and as consisting, when fully developed, of a cell wall composed of cellulose, lined with a semi-fluid, nitrogenous coating." With him, therefore, the cell consisted of two parts, viz., a vesicle and semifluid contents. In plants the cell forms are distinct, and easily recognized, and thus, when the conception of a similar elementary organ was extended to the animal kingdom by Schwann, in 1838, it is not to be wondered at that the cellular form was expected to be universal. Schwann added to Schleiden's two elements a third — the nucleus — which he deemed also of essential importance, and to be present in all cells, if not always, at least in some stage of their existence. On his authority this threefold doctrine of the cell became universally prevalent for a time. I give here Schwann's original definition of his theory, as some points in it have been overlooked or forgotten in the mass of controversial writing this subject has provoked : —

" The following admits of universal application to the formation of cells :— There is, in the first instance, a structureless substance present, which is sometimes quite fluid, at others

SCHLEIDEN, SCHWANN, HENLE. 15

more or less gelatinous. This substance possesses within itself, in a greater or lesser measure, according to its chemical qualities, and the degree of its vitality, a capacity to occasion the production of cells. When this takes place, the nucleus usually appears to be formed first, and then the cell around it. The formation of cells bears the same relation to organic nature that crystallization does to inorganic. The cell, when once formed, continues to grow by its own individual powers, but is, at the same time, directed by the influence of the entire organism in such manner as the design of the whole requires. This is the fundamental phenomenon of all animal and vegetable vegetation. It is alike equally consistent with those instances in which young cells are formed within parent cells, as with those in which the formation goes on outside of them. The generation of the cells takes place in a fluid, or in a structureless substance in both cases. We will name this substance in which the cells are formed, cell- germinating material (zellenkeimstoff), or cytoblastema. It may be figuratively compared to the mother-lye from which crystals are deposited " (Syd. Soc., 1847, p. 39).