W y L tA lJ''t^L^CLi><^iJL&-n^^ r (y /-* * iiJ^/yi^L^'i-t to THE VITALITY AND ORGANIZATION OF PKOTOPLASM BY ) ] EDMUND MONTGOMERY AUSTIN, TEXAS: GAMMEL-STATESMAN PUBLISHING COMPANY 19 04. THE VITALITY AND ORGANIZATION OF PROTOPLASM BY EDMUND MONTGOMERY. AUSTIN GAMMEL- STATESMAN PUBLISHING COMPANY 19 04. \ CONTENTS. VITALITY. Introduction 5 Ontogenetic Perplexities , 6 Molecular Theories Examined 10 (a) Polarigenisis — Herbert Spencer 10 (b) Pangenesis — Darwin 12 (c) Perigenesis — Ildeckel 14 (d) Mcchanico-Pliysiological Theory — Naegeli 16 (e) The Continuity of Germ-Plasm — Weismann 20 Summary 25 The LivrNC, Substance and Its Properties. Introduction 30 Vital Motility : 31 Assimilation : 40 Depuration 45 Growth and Reproduction 46 General Remarks 50 ORGANIZATION. Introduction 53 The Unity of the Oi'ganic Individual ..♦ 54 Organic Differentiation 58 Germ-Plasm and Its Organization 62 Segmentation 68 Formative Stimulation - 71 Fertilization 72 The Problem of the Living Form 79 VITALITY INTRODUCTION. The problem to be here considered is that of vitality. The things we perceive consist of what is physically and chemically designated as "matter." This irrespective of whatever theory may be formed regard- ing the real consistency of what is thus designated. In plants and animals this material substance is found to be alive. It manifests the peculiar phenomena that are called vital, and which essentially distinguish living beings from lifeless things. It is, therefore, above all, incumbent upon biologj^ as the science of life, to seek to ascertain the special conditions which give rise to the vital properties of the substance composing plants and animals. The explanation of vitality to be here advanced has been arrived at as the result of many years of observation devoted to the vital phenomena of primitive forms of life, such as the Protozoa. N"o general definition of life, such as philosophizing biologists have abundantly advanced, can here at all avail. Our insight into the pro- cesses which are operative in the manifestation of vital phenomena, has nowise been furthered by any of these conceptual abstractions. But neither, it must be confessed, has biolog}^, despite its minute investigations and diligent endeavors, as yet succeeded in disclosing the true nature of vitality. Guided by the cell-theory and purely me- chanical principles, it has vainl}^ searched for it in the minute structure, the intimate movements, and the chemical constitution of the single cells composing multicellular organisms; and quite especially in the striking occurrences accompanying their mitotic self -division. For, according to the cell-theory, complex organisms are made up of num- berless autonomous vital units or elementary organisms, which multiply by means of self-division. Such complex or multicellular beings have then to be regarded, not as being themselves unitary individuals; but, on the contrary, as being in reality aggregates of elementary units. In accordance with the cell-theory, each separate cell, as an autono- mous vital unit, must be the bearer of all that essentially constitutes vitality. Hence the minute investigation of every phase of its vital manifestations, of every visible trace of the changes it undergoes. But, however instructive in other respects, it can not be said that the result of all these patient and accurate observations, carried on by a host of competent investigators, has conduced to throw any decisive light on the real nature of vitality. It has failed to show how the sub- stance which composes the cells comes to be actually alive; how it is empowered to maintain its vitality and identity under constant change; 6 Vitality and Organization of Protoplasm. how it is able to transform lifeless nutritive material into living sub- stance; also by what means the cell gets to grow on its course towards self-division; and by what agencies such self -division is really effected. In fact, the intimate mode of operation of no fundamental vital process has yet been scientifically explained in current biolog}^ The difficulty of recognizing the real processes that give rise to vital activity and its visible manifestations ' was, moreover, perplexingly in- creased by the discovery of the mitotic self-division of the egg-cell. Here was seen what in keeping with the cell-theory, assisted by visible appear- ances, had to be considered a simple cell or elementary organism, con- taining, nevertheless, potentially all evolutional or developmental dis- positions, which under successive cell-divisions lead to the reproduction of a definite, intricately differentiated organism. Under this cell-theo- retical aspect, that which constitutes the vitality of the germ cell, in- clusive of its determinate vital potentialities, had to be considered either scientifically inscrutable, or it required for its plausible explanation — as amply exemplified in current theories — a set of far-fetched hypo- thetical assumptions, which bave no slightest support in real occurrences, or indeed in any known modes of activity. To clear the way for a correct insight into vital processes, it is im- portant fii'st to expose the insufficiency of the principal theories ad- vanced in explanation of the vital manifestations displayed by the germ- cell or the germ-plasm during ontogenetic evolution. For in the plasm of the germ-cell and its ontogenetic evolution all vital potencies are con- centrated. And attempts at their interpretation occupy themselves mostly with ontogenetic problems. The exposure of the radical insuffi- ciency of current theories being accomplished, it would leave the way open to show more effectively by what natural means protoplasm, of which the germ-cell and all living beings essentially consist, really comes to be alive, to be in verity what it is rightly called : the living substance. ONTOGENETIC PERPLEXITIES. In the problem of the reproduction of definitely organized beings from morphologically all but undifferentiated germ-cells or germ-plasm, is to be found the' most pregnant and significant task imposed upon bio- logical research. In order to account for the ways and means by which this wonderful formative process is effected, sundry hypothetical con- jectures have been offered by leading investigators. These have been generally conceived in analogy to prevailing physical thories. Ultimate elementary units are he^-e also assumed as composing the substance of the germ-plasm, and are hypothetically furnished with whatever en- dowments are required for the attainment of the given end in view. The explanatory difficulties which are encountered by supposing the germ-plasm to be composed of a cluster of elementary imits are, however, so perplexing, that strangely extravagant conceptions have to be resorted to, in order to render the interpretation at all plausible. Yet the need of such exceptional hypothetical assumptions arises almost inevitably Vitality and Organization of Protoplasm. 7 from what is actually witnessed as taking place in ontogenetic evolu- tion. For it is seen to start from a singile cellular being, the germ-cell, which divides into two "daughter-cells ;" these again divide, and' so on and on, until by means of such successive self-divisions the vast cell- aggregate is formed, which constitutes the complex multicellular organ- ism. Microscopically the complex adult organism appears to be thus composed of a countless number of elementary units, all the lineal off- spring of the one parental germ-cell. It is upon these plainly visible facts that the cell-theory is principally grounded. And its tenets seem not only ontogenetically evident, but ap- pear to be, moreover, confirmed by the existence of colonial forms, con- stituted by a number of more or less closely united unicellular beicgs, such as enter, for instance, in the formation of Volvox and Magisphoera. Some of these colonies bear a striking resemblance to the blastula stage of Metozoa, and strongly suggest the formation of these by union of similar unicellular beings. On the strength of such manifest evidence the complex organism of plants and animals was declared to be, not really the unitary being seen as such by unaided vision; but to be, on the contrary, a populous commonwealth composed of a multitude of autonomous elementary individuals, busily dividing among themselves the divers ontogenetic and physiological labors, which result in the com- plex structure, and the harmonized vital functions of the vast cell- aggregate they constitute. This sociological interpretation of the con- stitution of the complex organism was elaborated by Yirchow, Haeckel and others, and was generally accepted as a fundamental tenet of biologj^ Though, even with the assistance of sociological analogies, it is ration- ally inconceivable how the unconscious co-operation of numberless ele- mentary beings can result in the ontogenetic reproduction of the strictly predctennined, diversely constituted structures of an organic being, itself infinitely more complex and potent than any of the constituent cells; though, as conceived by the cell-theory, evolution of the adult organism through self-division of an elementary germ-cell, and its cellular progeny, is utterly incomprehensible, the cell-theory — seemingly enforced by visible demonstration — became notwithstanding a generally accepted doctrine, guiding biological research. It follows from its acceptance, that all vital efficiencies reside exclu- sively in the sundry discrete cellular beings, as autonomous units. And as ontogenetic evolution starts from one single such fertilized or un- fertilized autonomous being, the task thus given was to discover what endowments of the reproductive cell and its progeny lead to the divers- ified development ultimately represented by the manifoldly constituted tissues of the adult organism. How, then, does an epithelial cell, a muscle cell, a nerve cell, and all other varieties of cells ; how do they come to be potentially represented in the germ-cell? And how does this minute, morphologically all but undifferentiated cellular being man- age to evolve the huge structually differentiated form of the adult organism ? R Yl :33| 8 Vitality and Organization of Protoplasm. To answer these questions, even when the phyletic factors necessarily involved are left out of consideration, taxes the ingenuity of biologists to the utmost. Conceived as being itself an elementary organism, the germ-cell, like other elementary organisms, can consistently be expected to reproduce by self -division its own likeness only ; and not, as is actually the case, a morphologically most diversified and functionally utterly dissimilar progen3^ Biologists, who regard the germ-cell as a genuine self-dividing elementary organism, have sought to attribute the succes- sive differentiations and developments of its progeny to external causes and conditions, to which in the course of ontogenetic evolution the sun- dry cell-generations are diversely exposed. But, it must be asked, what imaginable external influences could possibly transform during onto- genetic evolution real elementary organisms, such as the germ-cell and its progeny are supposed to l)e, into muscular fibres, neurons, or merely into liver or lymphatic cells ; these forming, moreover, one and all, inte- grant constituents of a complex organism, whose form and structure are rigorously predetermined? To render so inconceivable a process to some extent plausible, the germ-cell is sometimes, despite its alleged elementary nature, hypo- thetically endowed with all manner of latent potentialities, which are believed to be respectively awakened to activity by specifically corre- sponding external incitements. These are then held to give rise, each in its special way, to the development of the sundry definite kinds of cellular beings. And as dormant potentialities of the living substance which constitutes cellular beings are known in some instances to be forced by external influences into undergoing definite normal or ab- normal modes of development, this hypothesis does not prima facie seem altogether fanciful. But in normal ontogenetic evolution no such specifically and adequately diversifying external causes can be detected. The reproduction of adult organisms of all kinds runs its course in essen- tially the same physical medium, and its specific distinctions, and there- with its structual differentiations, are evidently determined by inherent endowments of each special germ ; are in fact, strictly predetermined. The contents of the germ-cell, though not differentiated during onto- genetic evolution by external influences, must, however, in some man- ner possess within itself diversified potentialities, which in a suitable medium become then essentially self-evolving. In order to account for such manifoldly evolving endowments, the germ-cell is usually con- ceived as made up of a sufficient assortment of hypothetical vital units, such as gemmules, plastidules, pangenes, micelli, plasomes, biophores, etc., etc. And to the differentiated and differentiating endowments of these hypothetical vital imits are then attributed the diversely evolving characteristics of the cellular progeny. But here, under this supposition, another formidable difficulty arises to impede the progress of interpretation. For how docs it come to pass that the original contents of the germ-cell, as an elementary organism, which as such would in all its progeny reproduce only its own likeness; Vitality and Organization of Protoplasm. 9 how does it happen that its 'sundry constituent elements have come to be so diversely endowed as to be now fit respectively and conjointly to evolve into the disparate tissues of the adult organism ? In explanation of this strange evolution of heterogeneous and progres- sively higher offspring from an originally elementary organism, phyletic influences ,are necessarily invoked' And their differentiating and de- veloping effect on the ultimate vital units is then variously conceived by biologists; either as liability to assume specific modes of equilibra- tion, or as phases of unconscious memory, or again as sundry tropic sensibilities, or as other still more occult ontogenetic efficiencies. These divers ontogenetic potencies are generally believed to be wrought upon elementary units during phyletic elaboration by diversifying nutritive influences^ which are su23posed to bring about a progressive development of their molecular constitution, and therew'ith development of their respective potential endowments. Each elementary unit is then im- agined to become thus separately transformed into a specific germ of a specific tissue; and being so highly developed as now to be endowed with ontogenetic efficiencies enabling it conjointly with others to recon- stitute the specific form and structures of the adult organism. It is clear, however, that under this mode of interpretation the visible germ- cell can no longer be regarded as being itself an elementary autonomous organism, as it was at first supposed to be; but has to be regarded as being, on the contrary, at most, an ordered aggregate of diversely and highly endowed constituent elements. And this being the case, self- division of the germ-cell into genuine daughter-cells has therewith be- come impossible. For a cx)mposite of disparate or definitely ordered units, whether nuclear, somatip, or of any other kind, can not be con- ceived as producing by mere division qualitatively equal parts, or genuine lineal offspring. Consequently, under the supposition that the germ- cell was originally, or has become phyleticalh', composed of diversified or definitely ordered units, the cell-theor}^, the acknowledged basis of ontogenetic interpretation, is thereby virtually abolished. For it is of ■ ^ the essence of the cell-theory that by means of self-division equal "daughter-cells" are being produced. Here, on the contrary, the divi- sion of the differentiated aggregate can result only in the case of dis- parate assortment of units, in the production of two heterogeneous parts so far as their composition is concerned. And in the case of a specifi- , cally ordered aggregate of equal units, division can produce only com- ' pi omental halves or fragments of the ordered whole; but nowise genuine autonomous offspring. In fact, under the assumption of ultimate vital units, the cells of com- plex organisms can be merely differently constituted clusters of such multiplied vital units, without individuality of their own, and therefore without being themselves autonomous elementary organisms. The cell- theory, by assuming that its_cells are clusters of vital units, effects thereby ^ iis_a\ai dissolution. ' - Furthermore, on close inspection it becomes evident that, by assuming 10 Vitality and Organization of Protoplasm. the germ-cell to be composed of self-multiplying elementary units, the real problem of ontogenetic evolution has been simply shifted wholly unsolved from the visible germ-cell, as a whole, unto merely imagined constituents of the same. For it is now the vital units that reproduc- tively evolve, not the germ-cell itself. And these hypothetical, ultimate units have not merely to reproduce themselves, but have, moreover, con- jointly to reproduce the predetermined adult organism ; all this declared to be happening without the least insight into hoAv it is really accom- plished. And so we find ourselves again confronted by the double-sided riddle : How a group of specific reproductive elements, representing potentially the divers adult tissues, manage to originate and to become collected in the germ-cell? And how these autonomous units are then empowered conjointly to evolve the adult organism ? MOLECULAE THEORIES EXAMINED. Polarigenesis — Herh ert Spencer. * It is highly instructive and helpful to the view which will be here ad- vocated, to examine some principal attempts at elucidation of the para- mount vital and yet profoundly obscure problem of ontogenetic evolu- tion ; obscure under the hypothetical assumption that the adult organism consists really of a vast aggregate of autonomous elements. In recent times the first serious, though purely speculative, effort of the kind, was published in 1866 by Herbert Spencer in his "Principles of Biology," as part of his comprehensive scheme of cosmic evolution. In this his ingenious hypothesis, besides trying to account for given biological phenomena, he aims also to show that organic forms are special products or outcomes of the general redistribution of matter and motion, which atomic mechanics declares to be underlying the formation of all visible things. To render this mechanical mode of organic construction plausible, Spencer assumes the existence of highly complex organic molecules, which, in order to distinguish them from the molecules of lifeless or- ganic substances, such as albumin, fibrine, protein, etc., he calls "physi- ological units." These physiological units serve him not only as build- ing material, but they are also conceived as being the bearers of allvital and organic efficiencies. Each species of organism is held to be com- posed of a special kind of such units. And with the construction of the specific organic form in view, each kind of physiological units is en- dowed with appropriate "polarities." "Polarity" consists with Spencer in the tendency of each physiologi- cal unit to aggregate with other such units into the form of the organ- ism it helps to compose. Just as the atoms of a salt have the intrinsic aptitude to crystalize in a specific form. This interpretation of organic *1880, "Mind," No. XIX, Herbert Spencer's, Darwin's and llaeckd's theories were critisized from essentially the same standpoint. Vitaliti/ and Orgcmization of Proto plasm. 11 construction may seem to be plausible. But when wc desire to learn something more definite regarding this all-efficient intrinsic endowment of each physiological unit, predetermining it to aggregate into the spe- cific form of the adult organism it goes to compose, we are told that "it is a power of whose nature we know nothing;" "a name for some- thing of which we are ignorant;" "a name for a hypothetical property, which as such needs as much explanation as that which it is used to explain." Surely, this candid declaration amounts to a full confession that a wholly occult poAver, incapable of explaining anything, has been here arbitrarily invented, and made to account for all morphological and physiological phenomena of life. In mitigation of this sweeping con- fession of utter ignorance concerning the all-efficient power assumed to bo inherent in physiological units, and in order to correlate it with atomic mechanics, Spencer states that polarity "is regarded as a result- ant of forces and motions like those of sensible masses." If so, trans- mitted motion by impact can be the only influence that a physiological unit would be capable of exercising upon others. And this could result only, either in a rearrangement or vibration of their component elements, or in their bodily displacement, or in both these mechanical effects, ' How physiological units can acquire under such mechanical actuation their all-efficient specific polarities, x and how the minutely organized form and structures of a complex adult being can be evolved by their being mechanically shaken about, remains not only utterly enigmatical, but must be considered an egregiously inefficient hypothetical conception. Better to have adhered to the original confession of complete ignorance concerning the power that really actuates ontogenetic evolution. But, furthermore, how does Spencer, who may rightly be regarded as the first and foremost promulgator of universal evolution in the modern scientific sense; how docs he make the prodigious supply of physiological units arise, needed to compose the comparatively huge bullv of adult organisms? Incredible as it sounds, in utmost contradiction to his fundamental evolutional principle, which asserts that "construed in terms of evolution, every kind of being is conceived as a product of modifications Avrought by insensible gradations upon a pre-existing kind of being;" in oatright contradiction to this irrefragable law of evolu- tion, he lets the physiological units in countless multitudes come into being by sudden spontaneous generation. Considering that with Spencer the physiological unit is a product of endless pb.yletic evolution, in fact the highest product of evolution on our globe, its spontaneous gen- eration in vast shoals out of mere nutritive material is in the highest degree startling. He tries to mask this assumed spontaneous generation by attributing to existing physiological units "the power of moulfling fit material into other units of the same order." But it would be a truly miraculous power possessed by ph3^siological units, if they were really capable by mere contact with lifeless nutritive material to transmute the same into eminently specific and complex beings of tlie same species 12 Vitality and -Organization of Protoplasm. as themselves. Such sudden production of these his highest single beings on earth would afford a striking confirmation of the "special creation hypothesis/' to whose refutation Spencer has bent all his energies. But let a sufficient supply of physiological units be somehow furnished. From what source would they then derive their implied vitality? A physiological unit is, after all, conceived as a mere self-rounded chem- ical compound, though of a far more complex composition than other organic substances. At what stage of its phyletic elaboration could any- thing of a vital character have originated within it? Being, in fact, only a vastly complex chemical molecule, it could, if it really existed, be no more alive than any other chemical molecule. No manner of impressibility, due to its complex nature, could possibly invest it with any property that might rightly be called vital. And no ever so vast aggregate of them, however grouped, could display the least trace of vital activity. The fundamental assumptions of Spencer's hypothesis of Polarigencsis having proved utterly inadequate, the hypothesis itself has to be pro- nounced an out and out failure. The belief in the universal sway of atomic mechanics is accountable for this, and for similar theories of organic evolution. Starting with material atoms as building material, and taking their spatial arrange- ment into definite forms to- be simply the effect of mechanical modes of motion, theorists are readily led to ascribe definite shapes, and there- with definite directions of tension to their 'hypothetical units, believed to compose definitely shaped bodies. The specific structure and form of the latter, whether of organic or inorganic consistency, are then con- ceived as resulting from the equilbration of the shapes and tensions of the component units. But in such atomo-mechanical structures, if by mosaic-like arrangement of such material units the highly differentiated frame of complex organisms could really be constructed, there would be found in it no possible nook or crevice for vital activities to enter, and become functionally operative. The juxtajjosition of myriads of non- living elements, however grouped, can never result in the production of a living being. Pangenesis — Darwin* Darwin formulated his "provisional hypothesis of Pangenesis" under the conviction that like can produce only like ; and under the further conviction that complex organisms are really aggregates of diversely constituted autonomous cellular beincjs. Accepting the«e prevailing biological doctrines, he found himself logically constrained to conceive the germ cell, not as a genuine elementary organism, but as an asseuv- blage of reproductive "gemmules" derived from each different kind of adult cells. For the adult cells, as autonomous lieings. liave necessarily * See also '"Panii^enesis," p. 701 ; Jeiinisclio /citsclirift fiir Xatiii-wi^zpn- schaft, vol. XVIU, 1882. VHality (iiid Organlzdlion of rroioplasm. 13 each in its Ivind to bo represented in the germ cell. These germinal gem- mules Darwin believed to be thrown otl: by the adult cells at random into the circulation; whereupon an appi'opriate collection of each kind finds eventually its way into every germ cell ; wheref rem is then evolved in due order the respective kinds of cells by means of multiplication through self division of the corresponding gemmules. In support of this hypothesis of rej^rodiiction, the consistent logical outcome of the conceptions involved in the cell theory, a number of highly fanciful adjunct hypotheses have to be invented. For no known agency can be imagined competent to collect into germ cells from out the widely scattered chaos of coursing gemmules of all sorts; to collect therefrom an exact assortment representing each separate kind of adult cells. And no know^n agency can furthermore be imagined competent to mar- shal such a reproductive aggregate of gemmules in due order of onto- genetic evolution, so as to make them construct the specifically or- ganized structure of the adult being. Pangenesis, though a legitimate outcome of the cell theory, being thus forced to have recourse to various extravagant adjunct hypotheses, which transcend all legitimate infer- ence, is a theory which has in consequence to be declared untenable. With modifications Pangenesis has since served, nevertheless, as a necessary basis, upon which cell theorists have to build in order to ac- count for the phenomena of reproduction. But in their vei'y incep- tion, pangenic theories carry with them their self destruction. For the specific cells from which the hypothetical gemmules are derived have evidently to be first in existence before they can throw off repro- ductive gemmules, and their existence and production can therefore nowise be accounted for by the self-multiplication of gemmules to whose existence and production they themselves give rise; Moreover, it is the ontogenetic reproduction of the divers adult cells which is to be ex- plained, and, surely, it is not the least explained by assuming unexplained the reproduction of their hypothetical germs, to whose multifold re- production they owe their existence. Eeal visible reproduction is here merely hypothetical.ly delegated to the invisible reproduction of hypo- thetical units, without the least attempt to show in what reproduction itself really consists. Pangenesis is obviously laboring under insuperable difficulties by building upon the cell theory as a given basis, and it ends by destroying this very basis, from which it confidently starts. For cells, according to the cell theory, accepted by Pangenesis, are declared to be autonomous beings. In fact Pangenesis rests on this supposition. But how can the cells be autonomous beings when Pangenesis itself is forced to dissolve them info clusters of self multiplying gemmules? In keeping with the hypothesis, cells can indeed consist of nothing but aggregates of self -multi plied gemmules, and are therefore not autonomous beings. According to Darwdn's hypothesis the expected ontogenetic result would, however, be attained only if the substance of the cells, which are supposed to throw off reproductive gemmules w^ould be homogeneous 14 Vitality and Organization of Proioplasm. throughout. But cells prove to be, on the contrary, minutely differ- entiated and organized beings. This, at any rate, is the generally ac- cepted view. Pangenesis would then require, as Darwin himself asserts, special gemmules representing each differentiation of the cellular struc- ture, and this would so complicate the already untenable hypothesis as to amount, here also, to its complete overthrow. Pangenesis has been shown to be not only self-destructive, but de- structive also of the cell-theory, which it acce^Dted as the foundation upon which to erect its fanciful superstructure. Perigenesis — Hdecl-eh Haeckel found himself unable to adopt Darwin's h3^pothesis of Pan- genesis and offered in its stead, under the name of the "Perigenesis of the Plastidule," a different interpretation of heredity and ontogenetic evolution. Haeckel believes material atoms to possess certain psychical properties underlying their attractions and repulsions, and he assumes the plastidules or ultimate vital units of which he holds organisms to be composed, to be moreover endowed with memory, similar to that which Ewald Hering had ascribed to organic matter. To this psychical en- dowment of the plastidules he attributes the power of reproducing definite modes of motion caught up and impressed upon them during their phyletic interaction with external influences. Hereditary traits are thus held to be conveyed from generation to generation by means of these specifiically memorized plastidule-motions, which in the form of complexly cumulating waves are transmitted from the reproductive germ-plastidules to such as are thereby ncAvly produced in the course of ontogenetic evolution. With Haeckel, ontogenetic evolution x^on- sists, therefore, in a deployment and proliferating transmission of phyletically acquired wave motions emanating from the plastidules of the germ-cell. These transform by force of tbeir specific wave-motion at all stages of the evolutional progress nutritive material into equivalent plastidules, by whose co-operation the adult organism is eventually built up. To this rather strange hylozoic hypothesis it may first be objected, that from a scientific, and also from a philosophical standpoint it has been found inconceivable how a psychical property, such as memory, whether conscious or unconscious, can possibly set going any kind of motion. The postulation of a psychical moving agent undermines the very groundwork of physical science. Allow any sort of psychical influence to move matter, and there can be no further dependence on a physically ordered cosmos. But scrutinizing Haeckel's conception somewhat closer than he has himself been led to do, it will be found that it amounts, after all, only to a statement of a chemical fact in terms of hypothetical motion. For in his own words: "Conditions of nutrition change the chemical constitution, and therewith the molecular motion of the plasti- dule." And so it turns out, that it is the chemical constitution of the plastidule which is underlying its so-called memory, as well as its hj'po- VitalUij (Did Organization of Protoplasm. 15 tlietical wave-motion. It must, consequently, be at bottom the chem- ical constitution of the plastidule which undergoes developmental changes. And who will venture to assert that such evolving chemical changes are caused by the plastidule remembering, and therewith re- producing the series of wave-motions phyletically impressed upon it? The ontogenetic problem consists essentially in accounting for the gradual chemical and structural evolution of the germ-cell into the disparate tissues of the adult organism, and, surely, a hypothesis at- tributing ontogenetic evolution to the reproduction of cumulating wave- motions originated by memory is on the face of it an inept fiction. Moreover, it is wholly incomprehensible liow a progressive wave- motion can at all be transmitted in all its phyletic complexity to random nutritive material, so as to coerce it into chemical compounds of the same elaborated constitution as that possessed by the original wave- emitting plastidules. A profuse multiplication of plastidules is re- quired to build up the bulk of the adult organism. Can it possibly be furnished by mere contact of phyletically elaborated plastidules with nutritive material? No chemical compound whatever, much less one so highly wrought as a plastidule is held to be, can proliferate by trans- forming adjacent matter of a different kind into its own likeness. If this mode of proliferation really occurred, it would amount, in the case of a plastidule, to the spontaneous generation of the most highly evolved autonomous being in existence ; for such the theory asserts it to be. The plastidules, as ultimate bearers of all vital efficiencies, are therewith conceived to be the real organisms, of which the adult being is then a mere ordered aggregate. The ontogenetic problem seeks to find out by what means any kind of organism becomes reproduced, be it elementary or complex, be it a mere plastidule or the highest organism, and it is clear that Haeckel's hy- pothesis nowise contributes towards its solution. N"or does it contribute to the solution of the vexed problem of the formation of the germ-cell itself, as bearer of all ontogenetic potentialities. It leaves in the dark where its constituent plastidules originate, and how an appropriate assortment of the same comes to be collected in the sundry germ-cells. Nor, again,-- is it in the least clear how it happens that the plastidules are what may be really called alive. To hypothetically endow their component atoms and themselves with psychical faculties renders nowise their own vitality and that of the adult organism scientifically intelli- gible. Strangest of all, that Hacckel should call this psychically actu- ated vital theory "mechanical." Furthermore, and finally, Haeckel, a cell-theorist par excellence, dis- integrates in this his molecular theory of reproduction the absolutistie "Zellenstaat," of which, according to his view, we ourselves, and other complex organisms are a mere collective appearance. For, assuming the cells to be mere clusters of individualized plastidules, their own autonomous individuality is completely lost by thus delegating all vital properties and activities to the plastidules composing them. Here also \ 16 Vitality and Organization of Protoplasm. this hypothesis of ontogenetic evolution, starting from the cell-theory, ends by refuting it. Mechanico-'physioJogical Theory — Na-egeli. In 1884 Naegeli published his elaborate "Mechanico-physiological Theory of Evolution." In this important work he also adopts the cell- theory, of which he was one of the principal originators. It underlies his explanation of phylogenetic and ontogenetic phenomena. Taking thus the multicellular organism to be an aggregate of unicellular or- ganisms, the lineal offspring of an initial parent-cell, the question here again arises : First, as to the means by which the successive generations of daughter-cells constituting the multicellular organism have become differentiated in its divers, highly developed tissues? and second, hoAV these widely differentiated cellular beings come to be as such potentially represented in the reproductive germ-cell of higher organism? To answer these fundamental biological questions, ISTaegeli assumes the existence of a gradually developed germinal substance, which he calls "idioplasm." This reproductive substance he endows with an in- trinsic tendency to undergo phyletic development, and also with the capability of being to some extent structurally and functionally influ- enced by external conditions; and he believes that it is the intrinsically originated and directed process of development which leads to phyletic evolution, whilst the external influences bring about adaptation to the environment. The idioplasm or germinal substance is conceived by jSTaegeli as being segregated from plasm composed of micellae, which elementary bodies he holds to be invisibly small organic crystals surrounded by a watery film. Primordially, micellae are said to arise spontaneously in albuminous solutions. Whereupon by force of their molecular activi- ties they arrange themselves into groups, which grow by intussusception of newly formed micellae, and then, as such, multiply by self-division. Through summation of the molecular forces of groups, whose micellae are similarly oriented, molar forces come into play, that initiate new chemical processes, by which specific plastic tissue-products are phylet- ically formed. And these being influenced in their formation, not only intrinsically, but also by external stimuli, are found to be adapted to their medium. It is in this way that in the -course of phyletic evolution groups of idioplasmic micellae become more and more differentiated, so as to con- stitute respectively the "Anlage" or germ of the variform cell-structures composing the com])lex organism. The idioplasm of the germ-cell of a multicellular organism consists, therefore, of as many divers idio- plastic germs, or differentiated groups of micellae, as there are differen- tiated cells in the adult organism to be reproduced therefrom, and these are reproduced in the order in which the pliyletic development of the specific groups of micellae has taken place. The germinal potency of the idioplasm is. l)y moans of growth and Vitality and Organization of Protoplasm. 17 self-division, transmitted in its developed and developing condition to every cell, and is therefore continuous in phylogenetic as well as onto- genetic evolution, lii lower plants every cell has complete reproductive power. In Jiigher plants and in higher animals this power of repro- ducing the entire adult organism is, however, delegated to special germ- cells. According to Xaegeli's views, the idioplastic substance consists at every stage of phyletic development of single filaments of equal and equally oriented micellar groups. These filaments are believed to grow lengthwise by self-division of their micellar groups. In the course of further phyletic evolution, filaments whose micellar groups have become differentiated arc developed alongside the primitive filaments, so as to form fasciculse of diversely constituted micellar groups. In complex organism correspondingly complex strands of such filaments ramify in form of a network throughout the entire organism. These complex strands grow, as such, lengthwise through self-division of the micellar groups of which they consist. Each cross-section of idioplasm comes thus to contain a full assortment of micellar groups, and constitutes thus the "Anlage" or collective germ of the differentiated cells and tissues, to whose formation they give rise in the course of ontogenetic evolution. With Naegeli propagation, the supreme vital phenomenoa, is — as with Haeckel — merely mechanical division of overgrown groups of ele- mentary units formed by the intussusception of more f^nd more numer- ous like elements. To account for self-division of the germ-cell into an increasingly differentiated progeny, Naegeli does not, like Haeckel, endow his elementary units with a reproductive memory, acquired through unlike ontogenetic exposure to differentiating external condi- tions. He attributes organic evolution, with its increasing complexity of micellar structure and differentiation of vital functions, to an in- trinsic tendency of the combining molecular forces of the idioplastic micellar groups to give rise to the formation of higher organic beings; and he maintains that evolution once started in a given direction tends to continue in the same. jSTaegeli's answer, then, to the first question, which arises when or- ganic reproduction is contemplated from the standpoint of the cell- theory ; the question, namely,, how a self-dividing elementary organism, such as the germ-cell is conceived to be, comes eventually to propagate the differentiated progeny which constitutes the variform tissues of higher organisms; — his answer to this vexed question consists in an elaborate, but vain, attempt to apply mechanical conceptions to the vital phenomena here involved. Naegeli's vital units, the micellae, of which the entire organism is said to be composed, are mere crystals of organic matter possessing no trace of what really constitutes vitality. Intus- susception of new micellae into groups already formed, causing mere increase of their bulk, which he misnames "growth;" such mere aggre- gation of organic crystals can not rightly be considered a vital phe- 18 Vitality and Organization of Protoplasm. nomenon. Yet with Naegeli this mere aggregational increase of bulk is the fundamental and essential characteristic of life. As to the alleged causes operative in organic evolution, it is scien- tifically inconceivable how the molecular forces of separate micellae can affect the constitution of adjacent micellae divided by a watery film, so as naturally to differentiate and to develop their respective chemical composition. The separate micellfe neither chemically combine, nor can they cause among one another any kind of nutritive elaboration. How, then, under such conditions, by mere multiplication of micellae, and self-division of overgrown groups of the same, can these micellar groups come to be so diversely constituted as to form the respective germs of the differentiated tissues of higher organisms? And, above all, how come groups of crystalline micellse to be at all alive, to be real bearers of vital properties? Cells can be here only mere clusters of micellse themselves lifeless, and by no sort of grouping and combination of molecular forces across their watery film, can they be made to per- form the vital functions of higher organisms; to perform, indeed, the vital functions of the most elementary organism? And, surely, it is no less intelligible how idioplasm, which is held to consist of definite groups of divers organic crystals, can come me- chanically, by combination of their molecular forces, to be intrinsically endowed with a tendency to phyletically evolve. It is obvious, there- fore, that instead of a mechanical interpretation, an occult vitalistic principle is here introduced as the real cause of phyletic evolution, or as Naegeli calls it, "Autonome Vervollkommnung." But conceding to Naegeli all he claims for his phyletically evolved idioplasm ; conceding that the idioplasm of the germ-cell of multicellular organisms consists really of differentiated groups of micellae, each rep- resenting the specific germ of a specific tissue of the adult organism; conceding all this Naegeli fails to show how the differentiated cells of the adult organism are actually reproduced by the idioplasm. I'or, first of all, it is scientifically unintelligible how micellae, as vital and organizing units, can spontaneously form or crystallize out of albuminous solutions, or can be made to form in such solutions by the mere pres- ence of already existing micellae; and then it is visually and mechanic- ally unrepresentable how a specifically arranged group of micellae, and furthermore an entire cross-section of a complex strand of such groups, can divide and be thereby bisected into two equal parts, so that each part will contain an equal number of diverse micellae, grouped in the same specific manner as in the parent groups. No such mechanical division of complexly variform groups is conceivable. An infusorium, as a unicellular being, would consist, according to Naegeli, of a specific- ally ordered and oriented group of micellee. Try to divide it mechanic- ally lengthwise, or in any other way, and nowise could two equal halves, equal as regards the specific grouping of their micellae, be ever brought about. The division of an infusorium into two structurally equal be- ings is a specifically vital process transcending any mechanical mode of Vitality and Organizaiion of Protoplasm. 19 division, and the same holds good for cross-sections of strands of idio- plasm, which consist of manifold and divers groups or micellae. The cell-theory, Naegeli's original conception, is moreover virtually abolished by his conceiving the idioplasm as constituting a network of fasciculse, ramifying as a continuous substance throughout the entire organism, and giving origin to the differentiated cells of the ontogenet- ically developing organism. This can only take place, as he himself asserts, by the specific micellar groups, which form the "Anlage" or germs, giving rise to "the production of soma-plasm." We have here no longer an elementaiy parent-cell, which proliferates by means of successive self-divisions; all daughter-cells remaining autonomous units in the aggregate, which is held to constitute the multicellular organism. It is here, on the contrary, a continuous substance, consist- ing of complex strands of divers miscellar groups, whose every cross- section contains a full assortment of all micellar groups required to re- produce the different structures of the complex organism; it is a definite strand of such purely germinal substance, which from beginning to end directs and operates in every respect the entire ontogenetic reproduction. The germ-cell, from which ontogenetic evolution takes its start, is then no longer an elementary, self-dividing organism, but contains instead idioplasm consisting of a full assortment of micellar groups, which have as such to produce the diverse cellular structures of which they are the "x\nlage" or germ. This conception of an idioplastic germinal substance has been adopted by succeeding ontogenetic theories, which likewise falsely believe themselves to be grounded in the cell-theory. Furthermore, by what imaginable means can in the course of onto- genetic evolution definite sets of specific micellar groups, composing a self-rounded cross-section of ontogenetically inactive idioplasm happen to become separately active within the complex strand of which they form a part, exactly in time and at the very place where required during ontogenetic evolution? And how can a specific micellar group of idio- plasm as "Anlage," or germ, evolve by self-division or otherwise the specifically differentiated tissues, of which they are held to be the germs? How can they, for instance, not being themselves of muscular or neural consistency, produce muscular or neural tissue? It is clear that the en- tire problem of ontogenetic evolution is here also transferred wholly un- solved to hypothetical germs, consisting here of mysteriously originated, developed and arranged groups of organic crystals, themselves lifeless and ontogenetically inefficient. It follows from the few objections brought forward, to which many more might be added, that Naegeli's mechanico-physiological inter- pretation of "Autonome Vervollkommnung," or phyletic evolution by means of intrinsic forces, and that of "Anlage,^' or ontogenetic repro- duction by means- of specific groups of micellae, constituting the germs of specifically differentiated tissues ; that these essential tenets of his theory are untenable. And as some of the principal assumptions of the I I ' 1 20 VitaliUj and Organization of Protoplasm. theory are adopted by other current views of ontogenetic evolution, the exposure of their fallacy can not be deemed superfluous. The Continuity of Germplasm — ^Veismann. It is evident that in sexual reproduction the spermatozoon conveys somehow more or less completely the traits of the male parent. And as its head is found to consist almost entirely of nuclear substance, and to originate from nuclear plasm; as, moreover, this nuclear head is seen to unite during fertilization with the nucleus of the ovum under specifically figured karyokinetic deployment ; it lay near to look upon the nucleus as being the exclusive bearer of the germinal or reproductive sub- stance. And, forming part of the nuclear material, the chromatic sub- stance, by dint of its peculiarly regulated mode of fission and division, quite especially ofl'ered itself in the shape of so-called chromosomes as the veritable idioplasms, and was so designated by 0. Hertwig and Stras- burger. On this carefully observed and established foundation Weismann reared his ingeniously elaborated and widely celebrated theory of the "continuity of the germ-plasm." The chromatic plasm is actually ob- served to be continuously and directly transmitted during mitotic di- vision from one germ-cell to another. This direct observation of the continuity of what is taken to be germ-plasm seemed thus effectively to circumvent the insurmountable difficulties in the way of conceiving how a definite assortment of gemmules representing the different Idnds of adult cells, and detached from the same, come to be collected in germ- cells. This "wonderful" germinal representation of all kinds of phy^ letically evolved cells, as autonomous beings, in one and the same ger- minal receptacle, constituted for Darwin the principal phylogenetic and ontogenetic riddle. He asks : "How can the use or disuse of a particu- lar limb, or of the brain, affect a small aggregate of reproductive cells, seated in a distant part of the body, in such a manner that the being developed from these cells inherits the characters of either one or both parents ?" Weismann answers, that no kind of functional use or disuse ever af- fects the content of reproductive cells; that they exclusively reproduce their own phyletically inherited potencies, regardless of what modifica- tions of structure or function may have been acquired by the organism during its individual life. Under this essentially different view the task of accounting for the acquirement and rejiroduetion by the g^rm- plasm of the peculiarities of the structures of complex adult organisms was, however, only apparently facilitated. For granting that__phyletic evolution has been impressed on the continuous germ-plasm, the ques- tion how this germ-plasm has come to be phyletically differentiated and developed, so as potentially to represenf ^'^rifl onTogen'-ticaTly to repro- ^uco.the multifold structural and functional characteristics of the adult organism,_this fundamental quoslinn ])rov(s lier*^ tn be not a wliit less perplexing than the Lamarckian problem just (luotrd from Darwin. Vitality (ind Organization of Pruloplasm. 21 Although it is a fact that the germ-plasm evolves all tlie diverse tissues of the adult organism, it remains yet to be discovered how it has acquired its diiferentiated efficiencies, and how it manages atUially to realize' the same -during ontogenetic evolution. It was principally to "answer these questions that Weismann formulated his theory. Taking the chromosomes of the nuclear plasm to be exclusively germ-plasm, he necssarily conceived their structure to be of a highly complex nature. For how otherwise could they evolve the diverse structures of the adult ^ organism with all their specifically differentiated characteristics. The chromosomes must then contain special germinal representations for all the different specializations found in adult organism, and these repre- sentatives must occupy definite positions, and must be definitely grouped, in order systematically and in due sequence to evolve the differentiated structures. Each independently varying and inheritable trait of adult organisms, "even a mole on the skin, or a colored spot on the wing of a / a butterfly," Weismann believes, to be representatively pe4-formed in the /'"'''y/ germ-plasm by specialized component units of the same. These spe- / cializcd formative units he calls "determinants." because they are held ' respectively to determine the variform characteristics of the evolving structures of the adult organism. In the chrohiosomes the determinants are conceived to be specifically grouped so as to form complete assortments, representing every kind of structural differentiation destined to appear in the adult organism. Such complete assortments of determinants, definitely arranged within the chromosomes, Weismann names an 'JtcL^ And to explain certain biological phenomena he believes the chromosomes to be composed of a number of such ids, constituting what he names an "idant." The determinants themselves are held to be composed of a definite group of ultimate vital units, which Weismann calls '^biophorcs." These biophores or lifebearers are, like the gemmules of Darwin and the pan- genes of De Yries assumed to multiply by means of self-division. And Weismann not only allows his biophores or ultimate vital units, to mul- tiply by self-division, but makes his determinants, in which the biophores are specifically grouped, likewise multiply by self-division as a whole. And in the same manner his ids, in which determinants in full assort- ment are specifically grouped. And finally also his idants, in which a number of ids are held to be contained. Thus all different members of his hierarchy of differently grouped biophores are assumed to be en- dowed with the same vital property as the biophores themselves. JThey propagate their kind, and must possess, consequently, all vital efficien- cies inYQlved in reproductiop. It is obvious that under this theory the phylogenetic problem has to consist in showing how the biophores as original life-bearers come to be specifically differentiated, and speci&anv_group,ed, so as to form the vast supply of divers determinants required ; and how these determinants themselves come to be specifically grouped so as to form ids, and the ids again grouped so as to form idants. Xow the question is, have we any 22 ^ Vitality and Organization of Protoplasm. knowledge of agencies in nature that are competent to accomplish these tasks demanded by the theory ? All phyletic evolution has here to be immediately and exclusively wrought upon the biophores composing the germ-plasm; for they are held to be the veritable life-bearers, and the idioplasm they compose to be the only phyletically evolved and evolving substance. It is therefore relevant and essential to inquire by what known, or by what scientifically imaginable process the primordially equal biophores of the original germ-plasm can have been so profoundly affected that one set will now give rise to a liver-cell, while another set will determine the formation of a nerve-cell; while, in fact, divers sets or groups of biophores, all directly differentiated within the narrow confines of the chromosomes, will by self -division so propagate and so evolve as event- ually to constitute the multifoldly differentiated structures and execute the harmonized and unified functions of the adult organism? The biophores of the germ-plasm can be affected only by direct nu- tritive conditions. For, under Weismann's consistent theory, external stimuli, acting as evolutionally modifying agents, are strictly excluded. How, then can the sundry adjacent biophores composing the chro- mosomes be imagined to have been so differently exposed to nutritive conditions, as eventually to vary so widely, and to develop so prodigiously in their respective chemical constitution and formative potencies, as is here necessarily required ? No nutritive process, no germinal selection, aided by ever so favored and prolonged natural selection can possibly have brought about this state of things, upon which Weismann's theory is grounded. Weismann masks this cardinal difficulty of his theory by assuming that through mixture of male and female germ-plasm numberless va- rieties arise, which ^by means of selection of those best suited for the struggle of life^he progressive development of organic beings is brought about. It is,' however, evident that in order that progressive varieties can come at all into existence the biophores of the germ-plasm must have themselves first varied in the direction of useful organic progress. In fact, the very differentiation of male and female germ-plasm, with all their distinguishing peculiarities, can be due here only to differentia- tion of their respective biophores, of which the plasms are held to be entirely composed. All differentiation, and therewith all variation, and all progressive development, can originate only in the constitution of the biophores as ultimate vital units. This being so. no differentiation into male and female germ-plasm could have occurred had their biophores not themselves undergone such differentiation. Let the respective biophores of male and female germ- plasm remain at their earliest stage of differentiation unchanged from generation to generation, and no new varieties could have arisen from their mixture. Without varieties of biophores there can result no va- rieties of organisms by mixing them. And if the biophores believed to compose the germ-plnsm had failed to become tlieinselves progressively Vitality and Organization of Protoplasm. 23 differentiated and developed^, no progressive varieties of organic beings could have ever come into existence. No manner of mere grouping of biophorcs at a definite stage of their own development could give rise to tissues or organisms of a higher order than they themselves ger- minally represent. And with Weismann it is accordingly the specific- ally developed biophores of the determinants^, and not the determinants themselves as specific groupS;, that are said to transform indifferent soma-plasm into specific tissues. Only after the biophores have singly dispersed, dissolving their grouped connection, do they come to exer- cise their marvelous structure-determining influence. In every instance variation, development and formative potency have in this theory to be attributed exclusively to the biophores of the germ-plasm. Consequently, all phyletic and all ontogenetic efficiencies being incor- porated in the germ-plasm biophores, natural selection, as such, can nowise bring about any kind of organic change or development. It can consistently with the theory only select varieties whose progressive potentialities have been predetermined in the biophores of the germ- plasm. Natural selection is therefore no formative factor in organic development, as often surreptitiously assumed. And so the task re- mains, untouched by Weismann's theory; the task to ascertain what conditions have really brought about the progressive phyletic develop- ment potentially incorporated in the germ-plasm of higher organisms. Naegeli endowed his idioplasm with an intrinsic propensity phyletic- ally to develop, leaving thus progressive evolution a scientifically un- explained mystery. To believe, however, in accordance with the theory here examined, that mere nutritive accidental .variations of the densely clustered biophores composing the vitally sequestered chromosomes of nuclear plasm, have been competent so wondrously to differentiate and to develop these hypothetical beings, that they have become thereby fit to produce by self-multiplication, the divers organic tissues ; and conjointly to form, moreover, the eminently purposeful somatic configuration of the unitary adult organism, an organism functionally adapted out and out, and through and through, to a definite environment, upon wJiose constant, manifold interactions its very being and life are dependent, and with which the germ-plasm biophores are said to stand in no re- motest vital relation; — to believe and postulate so groundlessly inco- herent a state of things, in order to explain the most interdependently coherent and aimfully elaborated product of nature; this hypothetical effort affords, surely, one of the most glaring examples of elucidating obscurium per obscurius. But concede that the germ-plasm is really composed of biophores, and that these become in some way specifically differentiated and de- veloped, as required by the theory; let these biophores multiply by self- division and form specific determinants ; let, furthermore, definite assortments, of such determinants group themselves into ids, in which all distinctive traits of the adult organism are representatively pre- formed ; and let, finally, a sufficient number of such ids be grouped so 24 Vitality and Organization of Protoplasm. as to constitute idants ; — how, then, it must he asked, can these spe- cifically arranged gToups of divers biophores themselves multiply by self-division? How can the two resulting halves contain an equal as- sortment of all necessary determinants, without which no continuity of germ-plasm can exist, and without which the entire theory is vitiated in its most essential assumption? It is true that the chromosomes themselves, conceievd as idants, are actually seen longitudinally to di- vide. But no appearance points to their really consisting of so com- plex an aggregational structure as is here hypothetically assumed. Di- vision of determinants, ids and idants into two equal halves, under the supposition that they are composed of a diversity of self-dividing bio- phores, is simply inconceivable, as has been already stated in reference to any kind of specifically arranged group of diversified units. But Weismann's theory rests essentially on such equal division of specific- ally arranged groups of diversified units. For onl}^ division into equal halves can furnish successive generations with complete assortments , of determinants ; can, in fact, secure the continuity of the germ-plasm. Equal division of Weismann's germ-plasm being inconceivable, his theory is left without a sound foundation. It would be therefore superfluous to expose the fallacies involved in additional assumptions that have to be made in order first to consti- tute the manifold different groups of biophores; and then to marshal them in their way to achieve the stupendous task of constructing the adult organism with all its peculiarities of structure and function.* As regards the alleged unequal division of germ-plasm during onto- genetic evolution, which forms an essential tenet of Weismann's theory, it is effectively refuted by the demonstration of the formative totipo- jtence of fragments of egg-plasm. This important discovery upsets, indeed, all his ingenious groupings of biophores, together with their surmised ontogenetic potencies. It may here again be pointed out with advantage, that vital units, such as biophores are supposed to be, conceived as bearers of all essen- tial vital properties, are thereby constituted also bearers of the real process and entire secret of ontogenetic evolution. For their own propa- gation by means of self-division consists in the complete ontogenetic reproduction of new beings. They must therefore contain within them- selves all potencies that come into play during ontogenetic evolution and that underly the hereditary transmission of parental traits. And as the entire ontogenetic evolution of the complex adult organism is here wholly effected by the grouped progeny of proliferating biophores, the problem of ontogenetic evolution would, under this view, have to be solved, if it can be solved at all, not by making imaginary vital units hypothetically multiply and automatically group themselves into the organized form of the adult organism ; but by showing how the ])hyletic *This the present writer has to some extent attempted in a paper on "Mole- cular theories of organic reproduction," read before the Texas Academy of Sci- ence, December, 1805. Vitaliti) and Organization of Protoplasm. 25 and ontogenetic evolution of a vital being, such as the assumed vital units are held to be, is really brought about. And this means here, that the entire problem under consideration has been relegated -wholly un- solved to fanciful realms peopled by imaginary beings. Nor, it must be confessed, is it in the least intelligible how bioj)hores, however specifically developed, and emitted from determinants at the right time and in the right place, start suddenly into activity, trans- forming thereby indifferent soma-plasm or morpho-plasm into spe- cifically constituted and specifically functioning tissues. As they do not tliemselves consist of, for instance, muscle or nerve substance, how can they by their mere presence and self-multiplication determine the formation of muscles or nerves, or of any other kind of tissue? Or- ganic tissues can in this theory consist only of aggregations of self- multiplied biophores, which are able to determine or reproduce nothing but their own likeness. It is obvious, that in tliis theory also, as in all other aggregational theories, the cell-theory by which it is guided in its exposition, becomes in the course of its application disintegrated. The cell, as a self-divid- ing autonomous being, has dissolved into a multiplicity of other autono- mous self-dividing beings, and is no more itself. Finally, it has become extremely doubtful, if not wholly disproved, that it is really a nuclear plasm, which may rightly be called germ- plasm, the plasm that actually undergoes ontogenetic evolution, repro- ducing thereby the adult organism? It will be admitted that the fundamental assumptions of a theory, to be really serviceable, must be self-consistent, and must not logically lead to impossible interpretations of actual phenomena. SUMMAKY. It has been shown, that, under the supposition that the germ-plasm destined to reproduce a complex organism is composed of elementary units ; that under this aggregational view the leading theories of heredity and reproduction are untenable. Yet, assuming, as they mostly do, that higher organisms are really multicelhilar beings, composed of gen- erations of autonomous cells, which are the lineal offspring of a mother- cell, itself an autonomous elementary organism ; taking, in fact, the cell-theory as a safe foundation upon which to rear a theory of heredity and reproduction, they can hardly arrive at different conclusions. It seems, indeed, the only way to account for an elementary self-dividing being having come in the course of phyletic evolution to contain poten- tially the germinal differentiations, which under succes,sive divisions give rise to so divers a progeny as constitute the sundry tissues of higher or- ganisms. A cell, being by definition an elementary organism, can legitimately reproduce by means of self-division only its own likeness. But here it is found to reproduce successively differentiated generations of off- spring mostly more highly developed than it is itself supposed to be. 26 Vitality and Organization of Protoplasm. Somehow^ then, the widely differing cells of multicellular organisms, when conceived in accordance with the cell-theory as autonomous be- ings, have to be all germinally represented in the reproductive cell. Hence Spencer's multifoldly polarized physiological units, Darwin^s specifically differentiated gemmules, Haeckel's memory-endowed plasti- duies, Naegeli's intrinsically developing micellar groups, De Trie's in- tracellurally competing pangenes, Weismann's nutritively differentiated and diversely grouped biophores, etc. But by supposing the germ-cell, and still more by supposing the nu- clear germ-plasm to be composed of differentiated elementary units, through whose multiplication and grouping the adult organism is con- structed, you not only completely destroy the autonomous and elemen- tary nature of the germ-cell itself, as defined by the cell-theory ; but you dissipate during ontogenetic evolution the entire cell-theory, from which the evolutional start was so confidently made. For each kind of cell that composes the adult organism can then be nothing but a cluster of the multiplied particular units, by which it was representatively pre- formed in the germinal substance. Furthermore, the difficulty in the way of explaining by what means the vital units, supposed to compose the germ-plasm, have become so widely 'differentiated and diversely developed as now to be able to re- produce entirely different and more highly endowed cell-generations; this difficulty proves to be insuperable. For it is scientifically incon- ceivable how the originally equal units held- to have composed the pri- mordial mother-cell, all exposed to the same nutritive conditions, can have by any known, or legitimately inferred means come to be so widely differentiated and so highly evolved, as the theory demands. And if the varied external influences or stimuli, to which successive cell-genera- tions have been exposed, are here invoked to account for their differen- tiations, then Darwin's untenable hypothesis of pangenesis is logically necessitated; each externally differentiated cell has therewith to emit germinal representatives, definite assortments of Avhich have by some wholly unaccountable means to be collected within the reproductive cells. And this, surely, is a scientifically inadmissible assumption. As to Haeckel's substituted hypothesis of perigenesis, by which he seeks to explain the progressive differentiations of ontogenetic evolution, it was found to be really based, not — as he contends — on the drastically unscientific hylozoic assumption of memorized wave-motions of the plastidules, but on their supposed differentiation of chemical constitu- tion. At any rate, no less than in Darwin's ]iangenesis have distinct representatives of the diversely constituted cells of the adult organism to find their way into the germ-cell, which would necessitate super- natural intervention; for never could they, unaided by some Deus ex machina, reach their appointed destination. Moreover, the differentiated and highly evolved ultrainieroscopioal units here hypothetically assumed have to multiply in prodigious num- bers in order to build up the comparatively enormous bulk of the adult ViluUiy and Orgaiuzaiion of Proioplasm. ~ 27 organism. And this can take place only : either by spontaneous genera- tion, as taught by Spencer, Haeckel and Naegeli, or by self-division, as assumed by Darwin, De Vries and Weismann. Under the first sup- position, that of spontaneous generation, the essential tenet of the gen- eral theory of evolution is being egregiously contradicted. For this leading theory emphatically maintains that only by most gradual phy- letic elaboration can such highly developed vital units have been pro- duced. And here, in direct opposition of this irrefragible rule of evo- lution, countless numbers of just as highly constituted units are de- clared to be spontaneously and suddenly formed out of mere nutritive material. To such straits are foremost advocates of organic evolution pushed by the logic of their erroneous premises! Their highly com- plex organic units are conceived as specific chemical molecules. And no chemical molecule, even of the most elementary composition, can by its mere presence transmute different chemical molecules into its own likeness. Much less can the chemical units here assumed, which ac- cording to the theory arc the most highly developed single beings in ex- istence, have power to transmute by their mere presence or otherwise random nutritive material into their own consummately elaborated con- stitution. Nor can it be scientifically conceived when and where vital properties can possibly effect their entrance, or come into existence, among the groups of chemical units held to compose the tissues of adult organisms. And here it is important to remark that we are indirectly touching upon the pre-eminently vital problem of assimilation, and therewith of genuine organic growth, which is something entirely different from mere increase of bulk through accumulation of separate units. It is safe to say that this essential vital activity, which underlies growth and reproduction, can nowise be scientifically interpreted by aggregational theories. A vital imit has no power to produce other vital units out of nutritive material, and cause thereby genuine organic growth, lead- ing ultimately to the development of adult organisms, as maintained by Spencer, Haeckel, Naegeli and others. The other alternative, adopted by Darwin, De Tries, Weissmann, and their followers; the alternative, namely, of proliferation and increase of bulk by means of self-division on the part of the asumed vital units ; this supposition leaves likewise the entire problem of assimilation un- solved. For it is clear, that in this case the iiltimate vital units have first of all themselves to grow by assimilation of nutritive material be- fore they can divide. And this is exactly the vital process that has to be explained. We desire to know how an organism grows from a germi- nal beginning to maturity under assimilation of nutritive material. And we learn nothing by being told that an organism grows to maturity because it is composed of constituent elements or units that grow to maturity and then divide. The process of growing to maturity by means of assimilation of nutritive material remains here entirely oc- cult, and this obfuscation involves all ontogenetic evolution. 28 Vitality and Organization of Protoplasm. Likewise, wholly obscured, remains the process of proliferation by means of self-division. For how does a complex vital unit divide into two equal halves? To do so mechanically, as is usually believed, it would have to be a mere cluster of still more elementary equal units, while if it is conceived as an organic whole, whose component elements are diversly constituted and specifically arranged, it renders mechanical division into two equal parts impossible. We have here, then, in these asumed ultimate self-dividing imits, to face, wholly intact, the entire ontogenetic problem, for whose explanation they are expressly invented. Organisms of highly complex structure actually and visibly divide into two equal halves. How is this eminently vital feat accomplished? No valid explanation has yet been offered for it by current biology. Without assimilation of nutritive material no genuine growth, and without growth no reproduction. For reproduction is essentially evolu- tional growth of a germ to adult stature, by means of progressive assimi- lation. Obviously, then, before the fundamental and essential vital processes of assimilation, growth and reproduction are themselves scientifically explained, no valid theory of ontogenetic evolution can possibly be formulated. In the current ontogenetic theories, instead of explaining assimilation, growth, and reproduction, these fundamental vital pro- cesses have been simply taken for granted, and ontogenetic explanation has merely consisted in a more or less ingenious grouping of assimilat- ing, growing and reproducing hypothetical units. The aggregational theory, the theory that the complex organism is formed of clusters of autonomous units, is found to break down at every stage, and under every mode of hypothetical assumption. It meets its most grievous break-down, however, when the unitary organism and the unitary functions, of highly constituted living individuals are m.ade to be constructed and actuated by a multitude of autonomous elementary units. jSTothing short of a constant miracle could under these conditions bring into existence and maintain the intricately organized constitution of higher forms of life, and superintend, moreover, the blending of their separate and different elementary functions, so as to assure their har- monious co-operation; could, in fact, constitute the higher organism a functionally and morphologically indiscerptible whole. The myriads of vital units, in order conjointly and aim fully to con- struct the minutely and exquisitely organized frame of higher organisms, and harmoniously to actuate its divers and yet interdependent functions; in order to accomplish this prodigious task, these innumerable elemen- tary beings would have to be endowed with psychical powers and co- operative skill infinitely surpassing anything we are conversant with even in the highest living beings. These plain objections to aggregational theories, repeatedly urged by I the present writer in English and German periodicals during the last j twenty-five years have hitherto remained unheeded. They are, however, beginning to be corroborated by investigators occupied witli experi- Vitality and Organization of Protoplasm. 29 mental ontogeny and experimental regeneration. The striking phe- nomena of regeneration, and the discovery of the formative totipotence of single blastomeres, and even of small fragments of egg-plasm, are forcing upon biologists the conception, that_the_ complex organisni has to be look'cd upon as esentially a unitary _wholc. and not as a mere aggregate of a multitude of inferior beings. To apprehend at ji glance why aggregational theories have necessarily failed to explain ontogenetic evolution one need only recognize that by assuming a specific germinal unit, of whatever sort, to be capable of re- producing a definite kind of cell as autonomous being, be it k liver cell, a nerve cell or any other cell; that by adopting this aggregational hy- pothesis the entire process of ontogenetic evolution is therewith already presupposed and left wholly unexplained. For the multicellular organ- ism is being here regarded as a mere aggregate of diverse autonomous cells, and its collective germ-cells as mere clusters of germinal units, each of which possesses the powers to reproduce the kind of cell of which it is the special germ. And it is just as difficult to account for the evo- lution of a germinal unit into, for instance, a nerve cell, as it is to account for ontogenetic evolution in general. ■ Ontogenetic evolution of the multicellular adult organism can consist here only in the separate ontogenetic evolution of the germs of each kind of its component cells. The ontogenet'ic process running thus its full course unexplained in each germinal unit, it is in relation of the multicellular organism like- wise taken for granted in all its evolutional stages, from its germinal beginning to its completed evolution ending in the adult organism. It is, therefore, obvious that, despite most ingenious and diligent en- deavors on the part of a great number of competent investigators, the sway of preconceived doctrines has prevented them from gaining in- sight into the real process of ontogenetic evolution. They have merely given minute attention to its morphological appearances and results, without the remotest understanding of their mode of production. This can not be attained before the conditions which give rise to the vitality of the living substance are first understood. For ontogenetic evolution is only a special outcome of that which constitutes the vitality of the livinar substance. THE LIVING SUBSTANCE AND ITS VITAL PROPERTIES INTRODUCTION". Principally since Max Schultze's investigations Protoplasm has come to be generally recognized as the veritable living substance out of which organic beings are formed, as the specific chemical substance, which is the bearer of the vital properties, and which observably displa3's the same. Realizing that, without a scientific insight into the process or processes that constitute the life or vitality of protoplasm, biology lacks a solid foundation, the present writer has devoted a number of years exclusively to the study Qi..the vital properties _pf_ the living substance cojnpo-ing elementary forms of life. For we have here protoplasmic beings, mor- phologicallY all but homogeneous, which, nevertheless, move, react on stimulation, assimilate, grow and multiply. And these activities con- stitute admittedly the fundamental vital properties of all living beings, which are likewise essentially of protoplasmic consistency. By what means, then, is the living substance empowered to perform these sundry activities which constitute its vitality? Obviously, this is the question of questions underlying the science of life. It has been shown that, without an explanation of assimilation and growth, ontogenetic theories lack a sound foundation, and must con- sequently miscarry. They necessarily fail to give a valid scientific inter- pretation of the ontogenetic phenomena which lead to the reproduction of the adult organism. For they use, unexplained, for basis of their in- terpretation that which is to be explained; namely, the vital process q| ontogenetic evolution, only relegated here to the hyjwthetical vital units, which th^ the assumed life-bearers. And this they do, either by making these units spontaneously arise in some mysterious manner, or by making them multiply by self-division. And all this clearly involves the entire mystery of reproduction, for the explanation of which these units were expressly invented. The problem of ontogeny has. therefore, to be attacked from a dif- ^c / ferent standpoint. The original vital properties that underl/ onto- genetic evolution have first to be scientifically explained. ^ / In the realm of Protozoa, looked upon as unicellular beings, we have at our disposal for research a vast array of diversified, and yet most simple forms of life. As these diverse protoplasmic individuals all display the fundamental vital activities, by means of which they prove to be alive, it is evident that if that which constitutes life in jroneral Vitalifij and Organization of Protoplasm. . 31 can ever be explained, here we have offered to us the most promising Held for investigation. In suitable specimens all_ vital phenomena are openly displayed in visible transparency. And it can not be denied, thatThe adequate scientific explanation of the vital phenomena of such protoplasmic beings, carries with it the explanation of the essential vital phenomena of all protoplasmic beings. The pai'ticular mysterious- ness^taching to life as a natural phenomenon would then be effectively dispelled, so far as scientific interpretation is concerned. But itls well to remind ourselves at this juncture, that the living sub- stance with all its properties is revealed to us in the medium of our visual j^^epts. What \\;e actually perceive are obviously visual phe- nomena arising within our own being. And, as such, they can be only symbolical, though definite, representations of the foreign existent whose activities are stimulating our sense of vision in specific ways. It is solely upon the evidence of these visual signs, consisting of definite spatial forms and movements, that we realize the presence and the activi- ties of the foreign existent, and draw therefrom our conclusions con- cerning them. This vicarious nature of our knowledge of the phenomena of life, ac- cruing to us symbolically, chiefly in the medium of our sense of vision, accounts sufficiently for the back-ground of mystery legitimately attach- ing to vital manifestations. This epistemoLogical fact has to be clearly borne in mind, in order rightly to correlate living being with the rest of sense-revealed nature. For the life of organic beings, though a far more complex phenomenon than other natural occurrences, is really no more nor less mysterious in its constitution and its activities, than are the constitution and the "actT?iHes~of unorganized and non-living sub- stances. Perceptible nature in all its modes of appearance belongs to one and the same order of nature. oSTo essential disparity in this respect obtains between bodies that display vital phenomena in out and out de- pendence on a non-vital environment, and such as display only what are called physical or lifeless phenomena. The study of protoplasmic beings yields an interpretation of vital phenomena at least as scientifically complete, though not as accurately measurable as is afforded bj the study of purely physical phenomena. These are likewise chiefly revealed and scientifically expressed in visual terms of expansion and motion, and, therefore, no less vicariously and symbolically, than is the case with vital phenomena. VITAL MOTILITY. To our sight the most salient evidence of being alive is the self-move- ment of organic individuals. An animal that no longer moves is held to be dead, or at least, to have its life suspended for the time being. - And as regards protoplasm, the veritable living substance in plants and in animals, its vital motility is quite conspicuously the visible nhenome- non, by which its being alive chiefly evinces itself. In case we succeed in disclosing the ways and means through which the motility of proto- 32 Vitality and Orgariizatioti of Protoplasm. - plasm is rendered possible, we shall have gained a scientific insight into that which principally constitutes it a living substance. Selecting suitable protoplasmic individuals as objects of investiga- tion, the sundry processes operative in the self-movement of their sub- stance are readily detected. And here protozoa, belonging to the Sarco- / dina, afford the easiest and clearest view~of the intimate workings' that ; underly vital motility. By carefully watching the emission and retrac- tion of their so-called pseudopodia; or rather by watching the outflow, stagnation, remelting and shrinking of the substance of their pseudopo- aia, the desired information can with certainty be gathered. In order to arrive quite unmistakably at the correct interpretation of what are the actuating causes when protoplasmic pseudopodia are seen forcibly to flow out into space, eventually to come to a standstill, and finally to shrink, collapse and be reincorporated into the body of the protoplasmic individual ; in order to gain an understanding of these Q^ fundamental vital occurrences it is best to select such amoeba, or such rhizopods as emit slowly long and broad pseudopodia, whose flow of granules and distinction of granular and hyaline substance clearly in- dicate what is really taking place. The most favorable specimens for the purpose I have met with were gigantic amoeba, whose long, ])lunt finger-shaped pseudopodia measured 0.8 mm. in diaineter. And almost ') , as favorable were gigantic difflua pyrifornis, whose pseudopodia were often equally as broad, and at times about three times as long as the shell, though in this latter case they were niuch more slender in propor- tion to their length. First, then, what causes the stagnation, shrinking and collapse, or the so-called contraction of the living substance composing the pseudopodia ? Definite, unmistakable signs prove it to be due to chemical disintegra- tion. The stagnation of the outflowing pseudopodia is seen to begin at the surface of contact with the medium, extending more and more deeply towards the axis of the protoplasmic cone or cylinder. This occurrence is clearly evidenced, first, by the slackening flow of the granules embedded in the substance near the surface, and. then, by that portion of thejjyaline substance brought into contact with the medium JDecoming itself flocculent and eventually granular. Complete proof that the change here observed is, in fact, the work of chemical disinte- gration, is visibly given in vesicles, or so-called vacuoles, forming within the disintegrating substance, in which are gathered the effete fluid products of disintegration, presently seen to be eliminated. Now, as to the influences that are causing this chemical disintegra- tion, they are readily detected. Any sort of contact or external stimu- lation tends to decompose more or less profoundly the highly complex rnd explosive constitution of the protoplasm. In this "sensitiveness" to stimulation consists its so-called "irritability," formerly considered the very essence of vitality, or, at least, its most characteristic mani- festation. On artificial stimulation an expanded pseudopodium, or arp entire expanded amoeba will instantly shrink or contract. And if the Vitaliiy and Organization of Proloplasm. 33 irritation be sufiiciently intense the entire substance of the amoeba will contract into a globule. During the formation of a pseudopodium an expanding surface is offered to the stimulating influences of the medium, and the ensuing disintegration, accompanied by contraction, is very ol viously an effect of these stimulating influences. The proximate cause of contraction is thus observably chemical disintegration induced byi external stimulation. Xormal stimulation functionally disintegrates the expanding living substance, and, in consequence of it, -it contracts. But something additional occurs during the contraction of proto- l^lasm; something most essential to what constitutes its vitality, and which imparts to vital motility one of its most characteristic features. Each functionally disintegrated portion or particle of protoplasm serves as restitutive material to other disintegrated portions or particles. A chemically^ equilibrating vital commotion is thereby set going, which spreads more or less vividly throughout the entire protoplasmic in- dividual. It is this process of reintegration by means of complemental chemical blending of adjacent portions of protoplasm that causes the remelting of the stagnated protoplasm of pseudopodia. And spreading from' part to adjoining part it gradually involves the entire substance of the functionally disintegrated pseudopodium, whereby it acquires the tendency to contract into globular form. Shrinking thus within itself, it ends by being reincorporated into the substance of the protoplasmic body, with which it chemically blends. This essential vital process of complemental restitution, by means of the chemical blending of portions^ of functionally disintegrated proto- plasm, can most conspicuously be observed when two or more stagnated pseudopodia meet, and thereupon visibly coalesce, contracting into glob- ular form. But in each separate pseudopodium stagnation on exposure to external stimulation is followed by a lively play of complemental restitution, by means of the chemical blending of adjacent portions of protoplasm to more and more complete reintegration, involving the en- tire substance of the pseudopodium as a formative whole, and causing the molecular commotion and the mass-movement in which the contractu phase of vital motility consists. But something still more profoundly vital is implicated in that which causes a pseudopodium to be reincorporated into the body of the proto- plasmic individual. Fragments of protoplasmic individuals have, as is well known, the tendency to reintegrate or regenerate the whole organ- ism from which they are derived. A disintegrated pseudopodium is really a fragment of the protoplasmic individual from which it has issued, and its reincorporation is partly due to its own tendency, as well as to that of the rest of the protoplasmic being, to become fully reinte- grated, and to form thus a unitary whole. We shall find in the course of our interpretation of vital phenomena that reintegration of the in- dividual, as a whole, from fragments of the same, is playing the most essential part in ontogenetic evolution. The living substance has generally been looked upon as pre-eminently 34 Vitality and Organization of Protoplasm. a contractil substance. But the reverse is really the case. The living substance is pre-eminently an exp^ansil substaiice. Its contraction forms . essentially part of the negative phase of vital motility, due to functional dis'integration. Expansion, on the contrary, forms part of its positive phase, due to functional reintegration. You irritate or stimulate an amoeba sufficiently, and it contracts into a globule. You leave it then to its own resources, and it re-expands, pushing forth one or more pseu- dopodia. The intrinsic tendency of protoplasm is forcibly to expand or spread out during functional restitution. The formative expansion of a protoplasmic pseudopodium is the visible manifestation of the cumula- tive reintegration of the functionally deteriorated substance of the body from which it issues. Pseudopodia during their outflow assume a more or less elongated shape, because on contact with the medium the substance of the surface solidifies and forms an envelope confining the flow of the expanding substance, which is seen to continue within the envelope or tube. This more or less rigid envelope is occasionally ruptured by an all too forcible inroad of new expanding substance, whereupon an additional pseudo- podium issues from the ruptured spot, forming a side branch, and giving rise to complex phenomena of vital motility. The real consistency of flowing protoplasm has been a great puzzle to investigators. It could not be considered a real fluid, nor a real viscid, nor a real celloid. For the manifold phenomena of its vital motility refused to be explained by any property possessed by these different states of material consistency. The progressive reintegration of the substance which forms the pseudopodia is evidently that which gives rise to its apparent outflow. This apparent outflow is produced, not by anything resembling the flow of a genuine fluid, but by the progressive expansion of protoplasm during its cumulative reintegration. What takes place here is an eminently active and vital formative process, and no mere passive outspreading of any fluid or viscid substance. Nor is it caused by any mode of inhibition. I know well the astonishing forma- tion of beautiful, flexible, winding, tube-like shapes, which shoot out of amorphous myeline when water is added to it.* But the formation of pseudopodia is entirely due to a process of cumulative chemical reinte- gration on the part of the living substance. That the apparent outflow of pseudopodia consists really in a cumu- lative chemical elaboration of protoplasm can on close examination be clearly detected in suitable specimens. At first only densely and coarsely granulated substance issues from the protoplasmic individual. ' During its apparent flow the substance is seen to become progressively finer gran- ulated, and finally a completely hyaline substance, the so-called exto- plasm, issues as cumulating result of the chemical reintegration. In *I have much experimented with the wonderful formative capacity of nye- line, and have succeeded in imitating with it ahiiost all forms of natural and morbid cells. The results were communicated in a paper read before the Royal X Society of London, December 20, 18GG. Viialiiy and Organization of Protoplasm. 35 contact with the medium the hyaline substance becomes functionally disintegrated, and therewith transformed again into granular substance. Active expansion by force of chemical reintegration constitutes, then, the positive, progressive phase of vital motility, while contraction on external stimulation constitutes its negative, retrograde phase. Chemi- cal reintegration winds up the spring of action relaxed by chemical disintegration. The force or energy expended during disintegration is thus restored during reintegration. This two-fold process underlies y» most fundamentally and essentially all vital activity. The struggle and interaction between disintegration on external stim- ulation, and reintegration by force of intrinsic chemical affinities, taking place amid greater or smaller supplies of expanding substance, give rise in certain cases, and very conspicuously, for instance, in hairs of certain plants, and in rhezopods such as Gromia oviformis; this antag- onistic and yet compensative process gives rise here to a most varied and complex display of partly progressive and partly retrogressive motions undergone by different portions of the protoplasm at one and the same time. And these manifestations of vital motility are further compli- cated by partial stagnations and partial remeltings of the same. AH these blending and diverging phases of vital motility produce in such cases a most perplexing confusion of appearances, which, however, can all be disentangled and explained by using the light here thrown upon the actuating agencies of protoplasmic motility. Various kinds of amoeba are met with, in which the antagonistic forces of disintegration and reintegration are completely harmonized or bal- anced; in which the retrogressive and the progressive phase of motility co-operate to form a continuously reconstructed and self-rounded proto- plasmic individual. Nothing can be more instructive than to watch, and to gain an insight into what takes place in such morphologically unorganized, and yet organically and functionally unitary protoplasmic beings. An individual ovoid being is seen to flow evenly across the field of the microscope. From the interior of its body, toward the basal or aboral pole, where nutritive corpuscles are gathered, there issues what is seen as a continuous flow of granular material, expanding and getting finer and finer granulated, until quite in front there emerges a perfectly hyaline substance, forming what may be called the oral, most expanded pole of the ovoid being. This foremost product of cumula- tive reintegration presents thus its fully expanded surface to the me- dium. Suffering thereby functional disintegration through contact with the same, the disintegrated portion is thrust aside by the pushing forth of new expanding material, and is left sliding down along the sides, helping there to form the gradually contracting envelope, getting more and more granular, and closing in at the rear collapsed, and ready to reinter by means of compl omental restitution the ascending current. It is by means of this cycle of definitely interdependent activities that the form of the organism is maintained and its steady locomotion ef- fected. Such highly instructive organisms have to be looked upon as 36 Vitality and Organization of Protoplasm. forming one single so-called pseudopodium, through the apex of which a renewed flow of hyaline material is ever maintained. In this manner only is its steady locomotion accomplished. The true mode of amoeboid locomotion is here visibly demonstrated, and all other attempted ex- planations of genuine amoeboid locomotion will be foimd erroneous. Since twenty-five years, 1879, "St. Thomas' Hospital Eeports," I have urged in English and German* periodicals this explanation of amoeboid locomotion as part of my interpretation of vital motility. I was surprised that, so far as I am aware, not before nineteen years had ^ elapsed was it corroborated. Rhumbler published 1898 observations,""] ^'' which led him to explain amoeboid locomotion in the same manner. J The same occurrence, which leads in its unimpeded fulfillment to con- tinuous locomotion, takes partly place in every pseudopodium emitted by amoeboid beings. The substance forming the pseudopodium would keep pushing out into space if a sufficient supply of expanding material *1881, Pliieger Archiv. p. 502-3, I said: "Bei dem in Fig. I dargestellten Moner wird es mit einem Blick iibersichtlich, dasz der lebendigen Bewegung ein chemischer Cykhis von Zersetzung und Wiederherstellung zu Grunde liegt. Es flieszt der morphologisch unorganisirte KOrper, unter Beibehaltung seiner ovoiden Gestalt, kontinuirlich in der Rielitung seiner Liingsaclise in den Ranm hinaiis. Es musz demnach das iiberaus lebrreiclie Protoplasmaindividuvim als ein ein- ziger, diireh die ganze Korperniasse gcformter Fortsatz aufgefaszt werden; ein Fortsatz durch dessen Spitze stets neugebildete, sich streckende Substanz her- vordringt. Man sieht deutlich wie diese voUkommen hyaline Substanz aus einer granulirten matrix hervorgeht iind sich nach Vorwarts zu Bahn bricht; wie sie dann liberwaltigt von auszern Einfliissen zur Ruhe konimt ; alsbald jedoch von neuem hyalinen Stoff durchbrochen und bei Seite geschoben wird ; wo sie ver- dichted und langsam schrumpfend die Wlinde des flieszenden Kfirpers bilded, urn zuletzt nach hinten zu als granulirte Substanz wieder in den aufsteigenden Theil des chemi\"schen Kreislaufs einzurtreten. Da aus der hyalinen Substanz durch Beriihrung mit dem Medium, durch funktionelle Zersetzung, schrumpfende und granulirte Substanz wird; da ferner aus der im inneren des Protoplasma- kOrpers geborgenen granulirten Substanz wieder hyaline sich streckend Substanz in stetigem Fluss hervorgeht; so ist es klar, dasz diese hyaline Substanz das Produkt der chemischen und funktionellen Wiederherstellung ist. Der durch auszere Einfliisze oder sogenannte Reize disintegrirte ProtoplasmakQrper vervoll- standigt sich wieder durch innere Mittel." / 1882, ".Jenaische Zeitsehrift fiir Naturwiszenschaft," p. 679: "Hier besteht das ganze Individuvim aus einen einzigen stest erneuerten Fortsatz, vmd das stetige Vorwartsfliezen solcheramoeboiden Wesen wird allein dadurch zu Stande gebracht, dasz imaufhSi'lich neugeformte, hyaline Substanz sich nach Vorn zu durch die Spitze des Fortsates hervordrangt. Es wird dadurch die an der Beriihrungsfliiche mit dem Medium zersetzte und schrumpfende Substanz bei Seite geschoben und neuer Raum zur Wciterbewegung durch den friscli hervor- brechenden, sich streekenden Stoft' gewonnen. Das sich auf diese Weise vorwarts bewegende Protoplasmaindividuum erhiilt, durch die vorn sich ereignende funk- tionelle Zersetzung, zugleich auch eine festere, schrumpfende Umhiillung. Das hiillenbildende Protoplasma, welches am Entstehungsort noch hyalin est, wird seitwarts geschoben und auf seinem Wege nach hinten zu immer mehr granulirt. Bereits seitlich, aber zumeist am hinteren Ende wird diese Hlillonsubstanz als granulirter Stoff wieder dem inneren aufsteigenden und regenerirenden Strom ein- verleibt. Dieser Strom, der von hinten nach vorn zu stetig an Geschwindigkeit zunimmt, wird von der granulirten, fliessenden Matrix gebilded, die den Haup- tinhalt des ProtoplasmakOrpers ausmacht und aus deren vorderem Ende man die hyaline Substanz als Spitze des ganzen Wesens oder Fortsatzes hervorbrechen sieht." YitalHy and Organizaliun of Protoplasin. 37 were' continuously furnished. Failing this supply its ])rolonged ex- posure to the stimulating influences of the medium causes profound disintegration and consequent contraction. This is demonstrated by certain amceba that generally emit numbers of pseudopodia, which singly expand and contract. The amoeba remains during such variformed activity either, stationary, or moves quite irregularly by means of its body being dragged along in the wake of one or the other of its expand- ing or contracting pseudopodia. At times, however, such aniooba come to form one single pseudopodium involving their entire substance, in which case they move straight, along, head foremost, through space, exactly like the ovoid being above described. I have depicted such an < amoeba in Pflueger's Archiv, Yol. XX Y, Fig. IX. I have also seen ) Arcella Ehby and Difflugia pyriformis move at times straight along in the same manner. The phenomena of vital motility prove conclusively that protoplasm is a unitary substance, all parts of which are interdependently bound together through wdiat is called chemical affinity, and its vital manifesta- tions are, consequently, due to chemical processes. The living substance being, moreover, a chemjcally cumulating substance, is therewith of difl'erent chemical constitution in its sundry ascending parts, though . f cn^Cl/\^v{ I forming altogether a unitary whole. Best manifest in such amoeboid " beings as form one continuously flowing pseudopodium, the living sub- stance is seen to assume by dint of its vital activities, and its interactions Y with the medium, a bipolar and bilateral shape. These intimate con- stitutional properties of the living substance sufficiently account for the hitherto mysterious phenomena of "polarity" and "bilaterality" found to exist in plants and animals. They receive here their scientific ex- planation by recognizing that the living substance necessarily assumes a bipolar and l)ilateral form as a consequence of its all -involving cycle of chemical activities induced by its relations to the stimulating influ- _ences of the medium. In 1880 I expressed these fundamental biological facts, which I had discovered during my protoplasmic investigations, in the following terms : "The protoplasmic projection, with its chemically cumulating substance, highest at the apex, next high at the' circumference, and with its direct dependence on the digesting substance, constitutes the primi- tive zooid, the veritable animal unit. All essential divisions and direc- tions j3f organization are predetermined and foreshadowed in its ra,cdg- cuTar constitution and activity. The entoderm and ectoderm, the longi- tudinal axis with its cephalic and acephalic pole; the transverse axes, that remain equal when the animal does not creep ; but that get dis- tinguished in size and import through the establishment of a dorso- ventral dift'erentiation, when the animal does creep ; all these funda- mental tendencies of organization are contained in the specific^ flow of theliying substance, and are invariably expressed in the shape of a proto- plasmic projection." Mind, "The unity of the organic individual." This interpretation of the primitive, formative factors of organiza- 38 Vitality and Organization of Protoplasm. tion advanced on the strength of my observations of the vital manifesta- >^ tions of Protozoa, have been lately confirmed bj Morgan as an in- leyitable conclusion from manifold, most instructive results yielded by (experimental regeneration and experimental ontogeny. Morgan asserts that "there can not be much doubt that both the polarity and the bi- laterality of the egg or of a piece of the egg, belong fundamentally to the same class of phenomena, and we are forced to the supposition that they are inherent peculiarities of the living substance." "Kegenera- tion," p. 248. I may add that the interpretation of .vital phenomena here given and found to result from the cumulative reintegration of the living substance as a whole, necessarily following its normal or abnormal disintegration; I that this interpretation yields, as will be shown in the section on organi- zation, the master key to the unlocking of the otherwise impenetrable phenomena of ontogeny, regeneration, and organic shaping in general. Protoplasm is a collective name, and not a substance of definite chemical composition, such as other analyzable organic substances. As living substance it is by no means, as sometimes supposed, of the same chemical constitution in different protoplasmic beings. On the con- trary, it is precisely the difference of chemical constitution which under- lies the multifold and profound differences of such beings^ structurally and functionally. The difference of, chemical constitution evinces itself morphologically in the definite configuration which each of the numer- ous kinds of protoplasmic beings assumes; 'and functionally in the more or less rapid reintegration of the functionally deteriorated substance. The higher the chemical constitution, the quicker the functional restitu- tion. With regard to ama-boid beings, close observation and comparison of many kinds, reveals that the alternate expansion and contraction of their pseudopodia is not merely a casually induced phenomenon, nor merely a means of moving and seizing nutritive material ; but that it constitutes the most essential and central manifestation of their vitality. An ex- panding, explosive substance is thereby offered to the stimulating in- fluences of the medium, resulting in more or less profound disintegra- tion by its clash with the same, whereupon the intrinsic restitutive forces gain the ascendancy, and a renewed wave of expansion beats against the functionally disintegrating influences. Tn sundry ways, with slower or quicker pulsations, all forms of amoeboid beings display in ever reiterated sequence the same see-saw motion of alternate ex- pansion and retraction. There are amceboid beings, such as the.Helio- zoa, that push out long and slender pseudopodia, Avhich quickly stagnate through and through, whilst others, such as reticulate Ehizopods, push out just as long and slender pseudo]wdia, that appear, on the contrary, vividly active by means of the rapid play of reintegrating and disinte- grating pulses, aided by the coalescence of joining pseudopodia. There are again amoeba which push out irregularly shaped, lobular ]iseudQpodia, consisting mostly of hyaline pul)stauce. wliilst others ]nisli out long, Vitality and Organization of Protoplasm. 39 cylindric or conic pscudopodia, consisting mostly of granular material. All these diflferenees of form and consistency, and many more, are due to differences in the chemical constitution of the living substance. Like form and function depend on like chemical constitution; unlike form and function on unlike chemical constitution of the protoplasmic individuals. But in all kinds of amoeboid beings functional disintegra- tion and reintegration of their substance underlies their vital motility; and, indeed, their entire vital activity. Without functional disintegra- tion protoplasm would not be a living substance, but just as little would it be a living substance without functional reintegration. It is to this two-fold, seemingly antagonistic, yet really compensative activity that it owes its vitality, by which it is so strikingly distinguished from lifeless matter. The living substance is, then, quite essentially a substance which has the power to reintegrate itself after suffering deterioration. Its normal function consists, in fact, in the harmonized play of disintegration and reintegration; definite reintegrating pulses responding to definite dis- integrating pulses. All ectodermic interactions with the medium take place under such functional pulsations. Vital function consists in spe- cific reactive responses of the living substance to definite incitements emanating from its environment. What has been positively ascertained regarding the agencies that actuate vital motility, reveals, then, unmistakably, that a protoplasmic being is a unitary individual or organism, whose entire living substance is formed and maintained by a cycle of out and out interdependent chem- ical activities. Disintegrating changes of its exposed surface involve reintegration, not only of the surface substance, but necessarily also in consequence of it, reintegration of the entire substance forming the unitary individual. The protoplasmic individual is, in fact, a chemical whole, all of whose constituent parts and elements form integrant, and nowise mere aggregated components. The identity of the whole, the identity of the entire protoplasmiclndividual, indispensable to its exist- ence as a unitary being, can be maintained only by its complete rein- tegration following whatever deterioration it may suffer, normal or ab- normal, functional or otherwise. The intrinsic power of the proto])lasmic individual to restore its identity as a whole when externally encroached upon is, as already stated, the most fundamental formative influence in the life of organic beings. The living substance, by its signal power of maintaining its identity, under change; its power of identically reshaping its organization when impaired ; by this power of reintegrating itself to full identity it be- comes the natural and naturalistic substance par excellence, the real prototype of what in philosophical conception is regarded as the essence and nature of that which constitutes substantiality. For it alone in our world renders possible that a body may undergo changes, displaying sundry modifications, properties, attributes, and whatever modes of c 40 Vitality and Organization of Protoplasm. activity, and yet withal remain identical. The living substance is in this sepse the only substance we have, or can have, any knowledge of. Protoplasm is often looked upon as a mere mixture of various organic substances, which in combination, or singly, are believed to "be the bear- ers of vital properties. But no kind of statical substance can be alive, or be the bearer of vital properties. Life consists essentially in the ever sustained chemical and dynamical^play of the _organigni_with its ,me- dium. In a publication of 1882 I said:* "As regards the chemical composition of the living substance, how could it ever be possible to ascertain the same? No analysis of such a synthetic unity, of a sub- stance that is throughout in constant chemical flux, can throw any light^ on vital motility, which is the immediate mass-manirestation of the in- divisible, self-rounded play between the continually reintegrated proto- "plasm, and its as continual disintegration by the influences of the medium." Recently Johannes Reinke, who has assiduously labored to ascertain the chemical constitution of protoplasm, has emphatically ar- rived at the same conclusion. He says : "Dead protoplasm is no longer real protoplasm, just as little as a watch ground, to powder continues to be a watch." He, therefore, likewise looks upon the protoplasmic in- dividual as an indiscerptibly organized whole, whose structure he there- with holds to be the "dominant" agency in functional activity. By close observation of visil)le occurrences we have. I think, succeeded in gaining some positive, not merely h5^pothetical, insight into the real nature of the living substance, and of that which constitutes its vitality; an insight far more profound and instructive tlian any aggregational theory has ever afforded. We have discovered the ways and means by which the peculiar chemical substance, called protoplasm, comes to be alive; and have found that it is a living substance only by dint of the cycle of chemical activities by which it is constituted and maintained during its interaction with the medium. ASSIMILATION. The fundamental process of alternate disintegration and reintegra- tion, which gives rise to vital motility, involves, as indispensable ad- juncts, nutrition and depuration. On the one hand it necessitates ap- propriation, preparation and assimilation of complemental material fit for recomposition ; on the other hand oxydation and elimination of waste products of decomposition. Food serves essentially as restitutive material, and not as is often asserted, as fuel which is supplying from outside by force of its oxyda- tion the moving energy, which sets an otherwise immobile machinery going. In 1870 (Centralblate fur die Med. Wiss. Xo. 11), the present writer published ohservations on the living muscles of locusts, which induced him to conclude, in opposition to tlie generally accepted views of Julius Robert Mayer, that the contraction of muscular fibres is not ■'Menaiselio Zeilsclirift fiir Xiitui\\ iszonsphafl. vol. X^■|l^. ]i. 080. Vitality and Organization of Protoplasm. 41 simply mediated by a machine-like construction of the same, but that chemical changes in the constitution of the muscular substance itself causes its contraction. "From these observations, I think, I may con- clude, that in the muscular fibre its contraction is not mediated by any kind of machinery, but that changes in the chemical constitution of the muscular substance itself are the cause of the entire process of con- traction." In 1881, in an article in Pfluger's Archiv. Zur Lehre von \ der Muskelkontraction," after two entire years of further observation, 1 ventured to advance a new interpretation of muscular contraction, in which I laid stress on the positive, reintegrative, expansive phase of muscular activity, as compensation of the negative, disintegrative,, con- tractive phase, which latter remains still the only one physiologically acknowledged. These observations made nutrition or the functional use of food, and oxydation or reduction of organic substances, appear in an entirely different light. The office of nutrition was recognized as having essentially to supply and prepare assimilative material fit to reintegrate the functionally deteriorated substance. And the office of oxydation evinced itself as having essentially to reduce the eliminable products or waste substances of functional disintegration. The assimilation of nutritive material consists in the power of the living sul)stance to fill the chemical gap caused by functional disintegra- tion. This direct conclusion from observable facts scientifically explains in what nutrition really consists, and shows how assimilation is ren- dered possible. The force which compels assimilation by causing life- less matter to be incorporated in the living substance, and to become itself thereby vitalized ; this vitalizing force consists in the avidity of functionally deteriorated protoplasm to restitute its chemical integrity. The current hypotheses of individuated molecular units have turned vital assimilation into an inscrutable mystery. Under their sway it remains utterly unintelligible how lifeless outside matter can possibly be converted into swarms of vitalized and vitalizing molecules, of which organisms are then supposed to be built up. The untenability of such aggregational theories have been here sufficiently exposed. It has been found that without a correct understanding of assimilation, and there- with of organic growth, neither self-division, nor other modes of repro- duction can be scientifically explained. For assimilation and growth are processes upon which organic reproduction in all its fonns is altogether dependent. We have now positively recognized that assimilation, or the vital and organic incorporation of nutritive material consists nowise in a mysterious new formation of vital units, either by spontaneous gen- eration, or by the self-division of already existing units: but that it is simply a result of chemical reintegration of the living substance by means of combination with complemental material. Of course, in a general way it is taken for granted that organs repair the waste they suffer during functional activity. Kut by what means such organic restitution is effected has hitherto remained in the dark. It is instructive to elucidate the process of assimilation by tracing it 42 Vitality and Organization of Protoplasm. in different kinds of amoeboid beings. By watching the slender, seem- ingly deadened pseudopodia of Heliozoa, we see all manner of stray stuff drift between their rays. Among the particles of foreign matter coming in contact with the far-reaching pseudopodia, only a few are specifically attracted and retained; evidently through what is called chemical af- finity. By combination with many such minute particles the sharp out- lines of the pseudopodia become gradually serrated. Their substance is undergoing progressive restitution through chemical union with the foreign complemental material. It is, in fact, seen gradually to re- melt and contract. Several rays in this state are often seen to meet and to coalesce, acting upon one another as complemental material. Contracting more and more they eventually form together a globule, which is drawn into the body of the protoplasmic individual, there to constitute a nutritive corpuscle. At times some large body, fit for food, gets entangled between the rays, which on contact with it rapidly dissolve, coalescing around it, so as to form a large globule inclosing the foreign body, eventually to be drawn into the protoplasmic individual to serve there as nutritive material. Nutritive corpuscles of this kind are found, as is well known, in most "fluent" protoplasmic beings. They have the function of preparing assimilable material fit to reintegrate the living substance after functional deterioration. This preparation of assimilative material is effected in the nutritive cor- puscle by chemical interaction between the enveloping protoplasm and , the nutritive material. In these stellar protozoa the rays become so deeply deteriorated as to remain exteriorized and deadened until redeemed to life by direct com- bination with complemental material. The preparation of assimilative material becomes in this instance a function of every pseudopodic ray. - The substance of each ray melts under direct union with externally supplied material, and elaborates then the complemental substance for reintegration of the entire being, enabling it to emit new rays. In more highly developed amoeboid beings the process of direct ex- ternal reintegration of the pseudopodia, exclusively by means of imme- diate union with foreign material, is transformed into a process of in- direct reintegration from within. The nutritive corpuscles, formed by partial assimilation of food material on the part of one portion of the amoeboid substance, are lodged in the interior of the protoplasmic in- dividual, and elaborate there the assimilable material for the complete reintegration of other portions of the protoplasm. In this manner one portion of the living substance comes to prepare assimilative material for the restitution of the other portion, which in consequence is enabled to assume exclusively the dynamical interaction with the medium. A digesting portion of the common protoplasm becomes thus subservient to a moving portion. And this means that the internal substance, or what in higher organisms is called the entoderm, has the function of fumishine; restitntive material for the substance that is brought into Vilalifij and Organizalioii of Protoplasm. 43 inimediato interaction with the dynamically stimulating influences of the iiiedium. The protoplasmic individual becomes thus a being with a two-fold, almost bipolar relation to the medium. At its outer surface it carries on Avhat may be called the dynamical interaction with its environment, suffering thereby disintegration. In its interior it carries on the diges- tion of nutritive material furnished by the medium, whereby reintegra- tion is effected. This evident subserviency of the internal digesting sub- stance to the externally active substance of living beings is pregnant with important dev(>lopmental consequences. For it is extremely prob- able that the incessantly maintained interaction of the chemically cumu- lating substance of the organism with the divers and definitely stimu- lating influences of the medium ; that this ceaseless reciprocal play leads to the gradual functional attunement of diverse parts of its surface to the diverse modes of stimulation, and therewith to structural elaboration and structural differentiation. This adaptive process would then neces- sarily involve corresponding adaptation of the entire individual, con- sisting, as it docs throughout of a chemically integral substance. We actually find the different surface structures of organisms respec- tively attuned in their functional activities to different corresponding modes of external stimulation. Such specific attunement must have been somehow brought about during phyletic evolution. And, surely, it is more likely that it has been wrought by constant interaction of the living substance with the externally stimulating influences, in which its most essential and culminating vital function actually consists; more likely to have been wrought in this way, than by accidentally useful nutritrive variations of composition having been offered for random selection to haphazard contingencies arising during the struggle for existence; whatever helpful adaptive assistance this may have rendered. Results of botanical investigation point to this formative and develop- m':ntal dependence of the living substance on its interaction with the sundry influences of the environment. The plant stands in more imme- diate dependence on its medium than the animal. For its sundry organs evolve to a considerable extent in dependence on the same stimuli, with which they will eventually remain in functional interaction. Considering that the functional activity of the entire organism takes altogether place in more or less direct interaction with outside agencies, and in more or less important relations to the same ; considering, further- more, that the interaction of their surface structures or ectodermic organs with the sundry stimulating influences of the medium consti- tutes their culminating activity, to which all other functions are sub- servient; considering all this, it lies near to conclude that in this very activity is to be found the fundamental and most essential formative and developmental process. Nutrition having proved to be essentially complemental restitution of a preformed, most specific constitution of the living substance, it can not possibly take a leading part in organic evolution, as is generallv believed. 44 Vitality and Organization of Protoplasm. Inferences regarding phylctic agencies are, hoAvever, apt to stray more or less Avidel}' from what has really occurred. To ayoid false expecta- tions and wasted lahor it is well not to forget that the organic indiyidual, together with its environment, are conjointly revealed to our perception chiefly in the symbolical medium of our visual space. We perceive thus definite forms representing on the one hand the organism, and on the other its environment. And from direct or compared changes in our field of vision we conclude that the changes in the organism have been induced by corresponding changes in the environment. We distinguish hereby, by dint of established experience, l^etween chemical composition and activity, and purely physical or mechanical composition and activity. And in the case of the organism and its environment, we rightly con- clude that the observed changes wrought in the organism are chemical changes induced during cetodermic activity by interaction with the physical incitements emanating from the environment. But we know as little the intimate nature of what in our perception appears as chemi- cal substance, as we know by what means physical agents are empowered to induce changes in the constitution of bodies. We symbolically per- ceive the results without being able to form adequate conceptions of the real nature of the activities, or of the actuating agents at work. Though we know for certain that the living substance has, and steadfastly main- tains, a most specific chemical constitution, we are explaining its vital phenomena only symbolically, principally in terms of visual perception. The adaptation of the structures of the 'organism to the functions, which they exercise in relation to external conditions, consists evidently in the chemical elalwration of the living substance into functionally adapted structures, which are perceived as out and out organized forms. Assimilation is the consummation of the nutritive process. And the vitality of the substance composing living beings, with all its principal manifestations, such as irritability, motility, growth, regeneration and ontogenetic evolution, must all remain enigmatical, so long as the true nature of the assimilative process is not understood. The transforma- tion of lifeless into living substance underlies all vital function. And this conversion of lifeless into living substance consists, as has been showTi, simply in complemental assimilation of nutritive material, by means of which the living substance is reintegrated, after it has suffered disintegration. It does not consist, as generally accepted, in the new- formation of vital units. The restitutive process, actuated by the in- trinsic affinity and avidity of functionally deteriorated protoplasm towards nutritively complemental material, renders alone possible the vital reaction, the motility, tlie growth, the regeneration, and the repro- duction of organic beings, togctl:er with the maintenance of their struc- tural and functional identity. Such sweeping generalizing from the vital phenomena of beings low in the scale of organic evolution to the vital phenomena of organisms in general, may appear overbold and unjustified to many, perhaps to most investigators. But we are dealing here with Ihe observal)le ]u-ocesses Vitality and Organization of Protoplasm. 45 which give rise to the essential vital properties of the living substance, of which all organisms are admittedly composed. These properties, which constitute protoj)Iasni tl.e one living_suii^iiLce in nature, and which are, in fact, tlic essential vital properties of all organism?, reveal themselves intelligibly in the morphologically uncomplicated and trans- parent forms of amoeboid beings. Here the sundry vital functions are not morphologically specialized in intricately organized structures, and to all appearance separately confined in definitely formed organs, but are still interdependently fluent to our view. And this allows their mutual relations and activities in the service of the organic whole to be satisfactorily ascertained and scientifically explained. DEPUEATIOX. To complete our understanding of the cycle of chemical activities that constitutes vitality, we have to gi\e a moment's attention to depuration, the other indispensable adjunct to vital activity besides nutrition, and well nigh its opposite, though interdependently connected with it. Dur- ing functional activity, during its functional interaction with the me- dium, the living substance becomes to some extent deteriorated. The effete products of this functional deterioration have to be eliminated, in order to keep the living substance undefiled and unimpeded in its activ- ity. This is one of the occasions for depuration. Moreover, the process of nutrition, during its elaboration of assimilable material, gives like- wise rise to the formation of effete products, which have also to be elim- inated. This is the second occasion for depuration. The functionally severed particles of organic substance are seized upon by oxygen and reduced to eliminable elements. There are, therefore, two different regions, and two different occa- sions, where and when depuration takes place ; the first, where what may be called the dynamical play with the medium occurs; and the second, where the nutritive processes are at work. The former we may designate "dynamical," the latter- "nutritive" depuration. In Protozoa these functions are in most cases visibly performed by depurative vesicles, which gather and eliminate the oxydized and fluidized waste products. In amoeboid beings the depurative vesicles, or so-called vacuoles, indis- criminately arise more or less numerously where and whenever needed. In ciliated Infusoria, however, they become definitely localized, and con- stitute then regularly functioning organs. In some, as in the Vorticelli- dae, one single pulsating vacuole ministers normally both to dynamical and to nutritive depuration. In others, as in Paramsecidse, a vacuole in the oral region ministers to dynamic depuration, and another in the aboral region to nutritive dejxiration. In Actinophrys sol, when the animalcule has first been made to shrink, the formation and eventually the definite localization of the depurative vacuole can be observed. This interesting localization of an organ in the making, I have described in the St. Thomas Hospital Eeports, 1879. Besides the two modes of fluid depuration occurring in Sarcodina, 46 _ Vitality and Organization of Protoplasm. solid imrticles of undigestible nutritive material;, and particles derived" from deteriorated protoplasm, are eliminated by being bodily crushed out of the vital cycle. Depuration brings the protoplasmic individual into a third direct re- lation of interaction with the medium, and especially with its atmos- pheric oxygen. The living substance stands thus in three different direct and vital modes of dependence upon its medium. Its vitality is conditioned and actuated by the three different processes of interaction which arise from these three modes of dependence. First, the stimulating process which specifically incites the ectodermic or dynamical functions; second, the nutritive process which furnishes the complemental material for rein- tegration; and third, the depurative process which necessitates the ab- sorption of atmospheric oxygen. These vitally indispensable modes of interaction presuppose an intimately pre-established harmony between I every structure and function of the organism and the conditioning and actuating factors of the medium. This proves that fundamental adap- tation of the organism to its medium is coeval with life itself at every stage of its evolution, as Gustav Wolff has pointed out in his masterly polemic against adaptation by means of natural selection. GROWTH AXD REPKODUCTIOX. The general conditions which give rise and which sustain the vital activity of the substance composing living beings, involving motility, nutrition and depuration, have in their essential characteristics been considered. There remains unexplained the growth and the reproduc- tion of organic individuals. After having gained an insight into the process of assimilation, indis- pansably connected with reintegration of the living substance, that which essentially constitutes organic growth becomes almost self-evident. Growth, when manifested to its full extent, consists evidently in the (power of a fragment of the living substance derived from an adult organism to reintegrate itself, so as to reproduce the complete adult form. In ordinary functional disintegration the identity of the adult organism is quite obviously restored by means of complemental reinte- gration through assimilation of nutritive material. The deeper the dis- intregation penetrates, the larger the specific chemical gap to be com- plementally filled. The disintegrated living substance forms thus a more or less disequilibrated chemical fragment of its former self, en- dowed with the power of reintegrating or regenerating under suitable conditions. This power of fragments of organism to reconstitute the entire individual is most strikingly evidenced l)y parts of the living sub- stance artifically severed from organic individuals. Trembly's experi- ments on the regenerative power of sweet water jiolyps, published as early as 1714, and Reaumur's experiments chiefly on earthworms, pub- lished in 1742, which experiments were repeated and extended by other investigators, remained more a source of wonderment than of scientific Vitality and Organization of Protoplasm. 47 enlightenment. Not until Grubcr's researches on "the artificial division of Infusoria/' 1884-5, and M. Mnssbaum's investigations of "sponta- neous and artificial division," 1884, and on "the divisibility of the living substance," 188G, was there a new fruitful impetus given to the attempt at scientifically explaining this astonishing process of organic reintegration. Wonderful and most instructive results have since been experimentally attained in this field of research by a number'of investi- gators; an account of which, with much original matter has been lately given in Morgan's excellent work on "Regeneration." It is becoming more and more certain that this power of fragments, detached from organic beings, to regenerate the entire adult form from which they . are derived ; that this regenerative_pjOwer is one of the most fundamental y> proj>orties of the living substance. As to the relative smallness of fragments capable of regenerating the entire organism, Lillie found that fragments of the substance of Stentnr, measuring only 1-27 of the volume of the adult infusorium, retain still the power to regenerate the entire individual. And still more decisive in this respect was the great discovery that single blastomeres, and '^ven mere small fragments of egg-plasm possess the power to reproduce the complete embryo. As early as 1870 Haeckel observed that pieces of the segmented egg of Medusae were capable of regenerating complete ani- mals. 0. and E. Hertwig, Bovery, Driesch, ]VIorgan and others found that Ly single blastomeres, or pieces of egg-plasm of sea-urchins reproduce the entire embryo. Wilson showed that similar results can be obtained with Amphioxus; Herlitzka with salamanders; Zoja with jellyfish; Morgan with fish, etc. It is certain, then, that even small fragments of the substance com- posing protoplasmic individuals of highly complex structure, and even fragments of their egg or germ-plasm, have power to reintegrate, regen- erate, or reproduce the entire structure and form of the organism from which they are derived. This process of gradual reintegration is evi- dently genuine organic growtji^ Consequently, organic growth does no- wnse consist in the new formation and aggregation of multitudes of sep- arate vital units, but quite essentially in the power of fragments of the living substance to reintegrate, regenerate, or reproduce the entire proto- plasmic individual from which they are derived.* On the strength of numerous instructively varied experiments on artifically induced regeneration, and considering that even small frag- ments of egg-plasm are capable of reproducing the entire embryo, it is, I think, not far-fetched to conclude that_normal reproduction is like- *"Da nun das Ziel des normalen Wachsthums zanz dasselbe ist, niimlicli die Herstellimf? eines vollstandigen Individuiims. so ist im Wesentlichen Wachsthum die Erreichuns einer bestinimten chemischen Vollendung der lebendiv, •J 50 Vitality and Organization of Protoplasm. GENERAL REMARKS. It has been shown in this section that a definite cycle of chemical ac- tivities constitutes protoplasm a living substance ; that its interaction with the stimulating influences of the medium, taking place at its chem- ically highest region, is its culminating function, to which all other functions are subservient; and that this state of things necessarily in- volves nutrition or restitutive assimilation on the one hand, and on the other hand depuration or elimination of waste products. Howsoever intricately differentiated into organs, tissues and compo- nents of tissues an organism may appear to sight, its structures are nev- ertheless out and out the visible substratum of this -manifoldly related and yet indiscerptible cycle of activities which constitutes the. vitality and governs the organization of all living beings. It inseparably under- lies the structural unity of the organic individual in all its varied forms of appearance. Although since Descartes' purely mechamcal views, and then especially since atomic mechanics have guided the interpretation of vital phenomena, many prominent biologists have, notwithstanding, felt compelled to as- sume, as help in their scientific explanations; a special vital force or agency operative in vital phenomena. The existence of such a special vital force Lotze first successfully combated in his celebrated article in Wagner's Handwoerterbuch der Physiologic. He clearly showed that that which had been called a "vital force" is a mere metaphysical fic- tion. And though thoughtful observers such as Johannes Muller, Claude Bernard, Liebig and even Virchow still adhered to the belief that some- thing transcending physical forces is operative in vital manifestations, the sway of atomic mechanics overruled until quite lately all attempts to introduce into biology modes of activity additional to such as are merely mechanical. The insufficiency of the purely mechanical interpertation of natural phenomena in general and of vital phenomena in particular, was forced upon the present writer during his protoplasmic researches, and insisted upon in various publications for the last twenty-five years. In its rela- tion to biology I have expressed this need of a more profound view per- haps most concisely in Pfiueger's Archiv, 1881, v. xxv, p. 534, of which I give a translation : "The power of regeneration is in all cases the me- chanically unaccountable energy of protoplasm to chemically reinte- grate itself. Consequently its actuating energies and even the mechan- ical capacity for work on the part of animal organisms, does not admit the application of exact physical methods. We have here before us as source of energy an explosive substance, which is ever restituting itself, and whose power of reintegration, grounded in endless phyletie elabora- tion, stands therefore in no direct mechanical relation to its environment. Neither the complemental restitution, nor the effects of stimulation, are here mechanically transparent. They are. on the contrary, to be looked Vitality and Organization of Protoplasm. 51 upon as processes in sharp contrast to modes of mechanical energy-con- catenations." The organized living substance is not, as has been so generally taught, a mere machine actuated by externally transmitted energy; but it is it- self the very source of specific modes of energy, differing altogether from the mere mechanical kind. Its functional reintegration is not due to mechanically transmitted modes of motion; but to its phyletically in- wrought power of regenerating its own specifically efficient integrity. And its functional reactions on external stimulation are nowise the equiv- alently converted energy of the stimulating influences; but an intrinsic response of its own generically accumulated wealth of organized power, qualitatively and quantatively incommensurable with the stimulating energy, which merely arouses to action its indwelling potentialities. When I first expressed this view, the introduction of other than purely mechanical mode? of energy, and especially of hypermechanical vitalistic modes, was considered scientific heresy, not deserving serious attention. Principally through the persistent efforts of Ernst Mach, other modes of activity or manifestations of energy, than the purely mechanical, are now allowed to play a part in the actuation of natural phenomena, even of the physical kind. In keeping with this more comprehensive view, and with manifold biological results and considerations recently arrived at, thoughtful investigators, among whom Driesch is most prominent and outspoken, have under various guises been led to make again use of vital- , istic modes of interpretation. They have become aware that vital phe- nomena are actuated by specific energies of their own, and not by me- chanically transmitted modes of motion. In this connection Eugen Albrecht in his ^'Vorfragcn der Biologie" 1899, says : "All vital hypotheses mentioned testify, by dint of their mere existence that beyond the physico-chemical analysis there must lie problems, uncertainties, which we feel without being able to express them in current mechanical terms. It seems to me that in all these vitalistic attempts a hitherto unsolved question makes itself more or less distinctly discernible; a question which in its full import does not occur and can not occur to the rigorous mechanist, which, however, per- haps constitutes the essential ground and real object of the contention. I mean the problem of the living form." The power of the living substance, and therewith of organisms com- posv5d of it; the power to reintegrate or regenerate its structure and form, underlies all other vital manifestations. It insures the main- tenance of the identity of organic beings, without which neither their structures nor functions could retain any permanency; but would from moment to moment degenerate toward complete dissolution. The re- integration of living individuals, after fimctional or abnornjal deteriora- tion is an immistakably observable vital manifestation, which obviously indicates that the organic individual is an integrant whole. And it evidently constitutes a mode of energy not operative in inorganic nature ; energy being defined as the capacity of performing work. Its specific 52 Vil.alHi/ and Organization of Protoplasm. nature is evidenced here by the peculiar work it is performing ; the work of chemically reintegrating the structure and form of organic beings, whose modes of reaction are mechanically unaccountable. It may therefore confidently be looked upon as vital and formative energy with- out losing its character as essentially a chemical process. A chemical fragment of the living substance represents a phyletically accumulated store of most specific potential energy. There is here no abrupt intro- duction of some transcendent kind of force or energy imposed from outside upon the chemical substance composing organic beings, and be- lieved to mould and to vitalize their structures. The living substance is by force of its own chemical composition structurally organized, and by force of its cycle of chemical activities vitalized. Vital energy arises here naturally and inirinsically from the chemical constitution of the substance composing organic beings, and is displayed in consequence of their functional interaction with the influences of the medium. It is obvious that the maintenance of the definite structure of protoplasmic individuals is the work of this formative and vitalizing energy. The definite chemical constitution of the living substance evinces itself to our spatial vision as a definitely organized form. If we, furthermore, ask what in reality constitutes chemical compo- sition with its specific modes of qualitative reaction, we have to confess til at this question transcends as yet the limits of our knowledge. Suf- fice it to say, that, whatever theory may be advanced with regard to the ultimate constitution of what is called matter, chemical constitution is clearly recognized as a mode of composition, differing from mere physical aggregation of equal molecules by forming integrant bodily units, of which all component elements are interdependently bound together by a specific bond which is figuratively called chemical affinity. And it is certain that the qualitative modes of reaction of such chemical com- pounds, which in organic beings give rise to such striking phenomena; that these specific modes of reaction are mechanically incalculable. Driesch conceives them as "intensive manifoldness," because they have their being, not in a spatially mechanical arrangement of parts, which could react on stimulation only in one single definite nianner; but sub- sist in a hypermechanical, superspatial, vital sphere, which admits of manifoldly complex modes of reaction on the part of one and the same spatially visible substance. ORGANIZATION INTRODUCTION, Tlie interpretation of vital phenomena given in the former section rests not on hypothetical assumptions, but on the direct obsen^ation of visible and always verifiable manifestations. Its principal outcome, besides the scientific explanation of vitality, consists in having estab- lished the fact that the organism is essentially an indiscerptible whole, and not an assemblage of autonomous elementary units; that all its parts are integrant and not mere aggregated constituents; that its structure and form can nowise be explained as the result of a coming together and marshaling of a multitude of separate beings, nor its functions as the automatically co-operative activity of a host of ele- mentary units. Form, structure and function are, on the contrary, the work of a self-roimded cycle of interdependent chemical activities, which constitutes the unitary individual's vitality or life. Organisms are avowedly protoplasmic individuals, products of the phyletic elaboration of the living substance, of which they are all com- posed. It has been shown that all essential vital phenomena: irritability, specific reaction, motility, assimilation, growth and reproduction, natu- rally result from the power of the living substance to restitute itself to full integrity or identity when functionally disintegrated, and also to an astonishing degree when artificially fragmented. The maintenance and reconstitution of the integrity or identity of the organism as a whole is the essential conjoint work of all vital functions. It has been proved by many striking examples, that artificial frag- ments, not only of so-called imicellular organisms, but also of highly complex "multicellular" organisms, have the power to restitute or re- generate the specific structure and form of the adult individual from which they are derived. And it has been here clearly demonstrated that this power of fragments to reconstruct the whole is due to their being specific chemical fragments endowed with the faculty of regen- erating themselves by complemcntal assimilation of nutritive material, or even by transformation of tLcir own substance, so as eventually to reform the typical whole of which they are a fragment. And it has K ^jH-t-^u'*!' J- '-^ also been shown that the living substance is a^ chemically cumulating j substance which involves the formation of the axes of organic individ- uals; their basal and apical "polarity," their oral and aboral pole, their bilaterality, and transverse axial distinctions; fundamental vital proper- ties hitherto altogether enigmatic. No aggregational theory of reproduction, even when formulated by 54 Vitality and Organization of Protoplasm. the most eminent biological investigators has proved logically tenable in its explanatory assumptions. And even when these are granted, no such theory has or can efficiently explain the fundamental phenomena of vitality, motility, assimilation, growth and reproduction. THE UNITY OF THE ORGANIC INDIVIDUAL. Visible appearances to the contrary, undeniable facts are forcing in- vestigators to look upon the morphological configuration of so-called multicellular organisms, as the functionally specified structure of a unitary protoplasmic whole. And more and more is it becoming evi- dent that no aggregation of separate units can, save by miraculous inter- vention, arrange themselves in space so as to form and actuate the inter- dependent organs and functions of the complex organism.* Leading botanists have already acknowledged the unity of the or- ganic individual. Strasburger in his inaugural address as rector of his university, 1891, p. 16, says : Until recently it was accepted that there existed no communication between the plasma of plant-cells. It had to be asked how under such conditions is the co-operation of the sundry cells in the service of the organism as a whole at all possible, and how can the plant as a unitary being be thus formed. The problem found its solution in the discovery that the plasm of the different cells is con- nected by protoplasmic filaments. These traverse from cell to cell and cause thus the living substance of a plant tQ be continuous. The plant, therefore, like the animal, constitutes a unitary living organism." r~Pfeffer "Die Entwicklung-" 1895. arrives at the conclusion that: "All I cells are correlated pieces of the whole uninterruptedly connected pro- L.toplasmic body." And Vines in his address as President of the Botan- ical Section of the British Association, 1900, feels justified in de- •■"'claring: "The general and perhaps universal continuity of the proto- plasm in cellular plants has been established. Hence the body is no longer regarded as an aggregate of cells, but as a more or less septated mass of protoplasm." It now devolves upon zoologists to harmonize the apparent multicel- lular structure of animals with their real indiscerptible unity. Here «lso the continuous consistency of the protoplasmic structure is evinced by established, and by newly forming, protoplasmic bridges ensuring the vital intercommunication of the contents of cells. According to the observations of H. Sedgwick Quart. Journal of Micr., Science, v, xxvi, 1886, all cells are during ontogenetic evolution as well as during adult life in protoplasmic intercommunication. Frommann in the article "Zelle," Eeal-Encyklopsedie der Gesammten Neilkunde, 1890, sums up the then attained knowledge regarding cells in the following words: "We can no longer, as was formerly the case, regard the body as being y *Sec "Mind," -Taiiuary, 1880, "The Dfpondcneo of Quality on Specific Ener- \ gies," a paper writtci\ to oppose Lewes' and Wundt's theory of "Functional In- difference," and wherein is proved the impossibility of autonomous units to com- bine their efficiencies without a combining medium. Vitality and Organization of Protoplasm. 55 formed by a mere conglomerate of cells, completely separated from one another by membranes and having independent lives. There exist, on the contrary, in the tissues and organs such numerous connections be- tween equal and disparate cells, that it is entirely justifiable to regard the body as a unitary mass of living substance, as a synplasm." Even Haacke, an out and out aggregationist and mechanician, by admitting in his "Gestaltung and Vererbung," 1893, p. 124, that "every cell of the organism is directly or indirectly connected with all the rest by pro- toplasmic bridges'' virtually acknowledges the unity of the living sub- stance composing the organic individual. It would seem that zoolo- gists are as much justified as botanists to conclude from the continuity of the living substance : "the unity of the organic individual," in opposi- tion to its formation ont of autonomous cells. But other stringent proofs of the unity of the animal organism are at the command of zoolo- gists. Eecent experiments on ontogenetic potentialities of fragments of egg- plasm and on the extent and efficiency of regeneration in general, have broken further decisive ground towards the establishment of the es- sential unity of animal organization. Eoux, although himself an ag- gregationist, has as early as 1885 drawn the logical conclusion that "if the germ does not contain definitely preformed germinal particles, then differentiation must be dependent on the influence of the whole of the embryo upon its sundry parts.* Eoux's own pregnant experiment, per- formed 1888, resulting in the formation of half -embryos, from one of the two blastomeres, when the sister-blastomere had been killed, involved unbeknown to him, the "influence of the whole of the embryo upon its sundry parts," and it involved, moreover, irresistibly, the complete over- throw of the cell-theory. For the two blastomeres proved by this de- cisive experiment to be, not what according to tlie cell-theory they would have to be, namely equal daughter-cells formed by the self-division of an elementary mother-cell ; but, on the contrary, they proved to be the po- tential embodiment of the complemental halves of one and the same organism to be ontogenetically evolved. It follows that all further stages of segmentation can not be anything in the remotest degree re- sembling the multiplication by self-division of autonomous cellular beings; but that they represent the visible segregation of strictly com- plemental parts of a predetermined whole in the course of being evolved. This is not a hypothetical assumption, but a positively observed fact. Pflueger's results gained by experime^jts with the eggs of frogs, pub- lished in his Archiv 1883, and formulated in his theory of the "Isotropic des Eiplasmas," led to similar conclusions. They proved that, though the different constituent elements of the egg-plasm are made to change their relative positions, a perfectly formed embryo is nevertheless pro- duced. And, even if it is true as Born seems to have shown, that no *Einleitxing zu den Beitras'en der Entwicklungsmeclianic des Embryo. Zeit- scrift fur Biologie, 1885. 56 TikiUty and Organization of Protoplasm. intermixture of the pigmented and the non-pigmented plasm takes place, but only rotation within the egg-shell; still, as different parts of the egg-plasm are found to be able to exchange their ontogenetic po- tentialities with regard to the evolution of the whole embryo, differ- u entiation must be somehow dependent on the influence of the whole on II its parts. This being the case, structural differentiations can not pos- ^ sibly be preformed in the egg-plasm as specific germinal units. All portions of the egg-plasm seemed here to be of equivalent potency as re- gards the reproduction of the .embryo. And, of course, in this case dif- ferentiation must be somehow* &ependeijt on the ijifluence of the whole upon its parts. As these experiments of Pflueger were essentially confirmed by E. and 0. Hertwig, Eoux, Driesch, Boveri and others, it is obvious that these investigators were thereby logically compelled, not only to acknowledge the influence of the prospective whole on its evolving parts; but they were also logically compelled to relinquish the aggregational theory of specifically preformed germinal units. Eoux, by confining the repro- ductive substance to nuclear plasm, evaded the biological consequences involved in Pflueger 's experiments. 0. Hertwig admitted that the whole exerts a formative influence on its parts, but nevertheless ad- hered to the opinion that differentiations of embryonic structures are performed in definite particles' of egg-plasm. Driesch, on the other hand, soon came fully to recognize the "^yeighty negative and positive consequences involved in the equal prospective potency of different parts of the egg-plasm. He repeatedly declared, that not only as regards form, but also functionally is the adult organism reproduced from the egg as a unitary whole. This view of the potential integrity of ontogenetic evolution, whereby all its structural differentiations, and all its pro- gressive stages, are subservient to the predetermined aim of reproducing the whole adult organism; this view follows indeed logically from the discovery of the equal "^'prospective potentiality" of different parts of the egg-plasm; the potentiality here of each such part being able to repro- duce the entire structure and form of the embryo. The recognition of this power of fragments to reproduce the whole is, of course, of para- mount importance to the science of life, as fully explained in the former section. It is the real formative power in all ontogenetic evolution and in all regeneration, and in fact a fundamental property of the living substance. As a result of his experiments on regeneration Eugen Schultz arived at the same conclusion. He says : "Eegeneration is a primary property of living beings." "Upon the original capacity of regeneration depends the evolution of the embryo." Biol-Centralb^att, V. xxii, Jan. 15. The entire drift of Morgan's admirable work on "Eegeneration" tends to establish the unity of the organic individual, and the subordinate part cells are playing in ontogenetic evolution. His observation that the diminished number of cells in fragments of the blastula has no in- fluence on the power of the fragments to regenerate the entire embryo, Vitality and Organization of Protoplasm. 57 affords sufficient proof that cells, as such^ are not the essential agents in ontogenetic evolution. And he finds himself compelled to conclude, "that the organism is not the sum total of the actions and interactions of its cells; but has_a struchire .of_its own^independ^ of. tlT£ .ijellg." ^Yhit- man, 1893, published a paper, Journ. of Morph., viii, "On the inadequacy of the Cell-Theory of Development." And a number of other inves- tigators have likewise arrived, more or less positively, at the concep- tion that the construction of the whole is, in the words of Driesch, "the clearly recognized goal of the entire process of development." The recognition that the whole is potentially predetermined even in fragments of egg-plasm excludes the possibility of its multifold struc- tural differentiations being represented in the germ-plasm each by a separate germinal unit, and consequently of its being constructed by an aggregation of autonomous cellular beings. The present writer has on the strength of his protoplasmic researches strenuously opposed the cell-theory, and advocated the unity of the organic individual for the Tast twenty-five years in a number of publications. I concluded my arti- cles' entitled "The IIiut;5L.pf. the Organic Indiyidual," Mind, 1880, with the following sentence: "To contradistinguish the theory of organiza- tion here briefly expounded from the prevailing cell-theory I call it the theorx, of Specification ; specification . of a single protoplasmic unit into definite areas of disparate stimulation; not association of a number of elementary organisms for the purpose of dividing among themselves a hypostasised physiological labor."* But here the question naturally arises,^how the whole, which is Jiot ^actually presen^t, which in fact is not yet in existence can possibly exert a preponderantly directive influence upon the evolution of the germ- plasm. The ancient puzzle of the priority of the whole over its parts, so fateful in philosophical discussions of the conceptual order, and pop- ularly expressed in the riddle: "What is first in existence, the hen or the e^gT' This profound puzzle, philosophically as well as bologic- ally, finds its solution by recognizing that the germ-plasm is not an aggregate of separate and disparate units, nor anything like an elemen- tary organism; but that all reproductive plasm is really a chemical fragment of the whole from which it is derived, endowed as such, by force of its indwelling most specific affinities, with the power of regen- erating it by means of gradual reintegration. The germ-cell far from being an elementary organism, is, on the contrarv, the potential embodi- ment of all phyletic elaboration. Without this chemico-vital conception, scientifically justified by actual observation and definite experimental results, thoughtful investigators will find themselves inevitably driven to vitalism of the deus exjnachina kind ; for it is certain that vital phenomena are hypermechanical and speciflcally vital. Of course, it has always to be borne in mind that *See also "The Dependence of Quality on Specific Energies," "Mind," Jan- uary, 1880, and "Are We Cell Aggregates?" "Mind," January, 1882. 58 Vitality and Organization of Protoplasm. what we call "chemical"' is a name for a definite set of phenomena ex- pressed in terms of sensorial affections, and mostly in those of visual space-manifestations; in fact in terms of visual consciousness. ORGANIC DIFFERENTIATION. It has to be asked : How do organisms come to be at all constituted and structurally differentiated as they are actually found to be? In order to gain a scientific understanding of the conditions that give rise to the shaping and definite organic differentiation of protoplasmic individuals, it will be best to have recourse again to primitive forms of life, where all vital activities take place in visible and transparent unity. Here we find certain amoeboid beings, whose living substance forms, as explained in the former section, one single, self-rounded pseudopodium or process, "exhibiting no trace of morphologically established organiza- tion; but forming nevertheless an organism composed of all the essen- tial appurtenances of complex vitality." "The entire chemical cycle constituting the organism and its vitality is here observable. It is dis- tinctly perceived how the complex chemical circuit gives rise to the definite location of all the chief differentiations found in advanced or- ganization." ("The elementary functions and the primitive organiza- tion of protoplasm." St. Thomas' Hospital Keports, 1879.) It will be seen that the attempt was there made to attack the problem recently pointed out by Driesch as only vitalistically interpretable ; the problem of the interdependent localization of the differentiated tissues that constitute the unitary organism. Driesch clearly recognized the im- \ possibility of solving it mechanically by mere juxtaposition of separate units, or dynamically by the influence of external stimulation. When venturing a solution of this obscure problem on the evidence afforded by the study of Protozoa; other evidence then lacking, I was well aware that on such meager grounds the interpretation ■ given would appear highly fanciful. I formulated the problem in the following terms: "Why, then, is the morphological unit (Paramecium aurelia) con- structed such as it is ? Why is it thus shaped ? Why has it an oral and an aboral pole, an integument, a contract] 1 layer, a digesting sub- stance, etc." Conscious of the boldness of proposing such an inquiry, I added : "These are questions that sound strange indeed, almost as emanating from the school of Schelling or Oken; yet it will presently be seen how completely justified they are from a strictly scientific point of view." ("The Unity of the Organic Individual," Mind, No. xx, 1880.) Now that with the help of experimental ontogeny and experimental regeneration investigators have penetrated more deeply than before the secrets of vitality and organization, it may be hoped that, assisted by this new light, the interpretation of these fundamental biological phe- nomena, reached long ago, and reiterated in English and German pe- riodicals, will no longer be overlooked. It will be found in essential Viialiiij and Organization of Protoplasm. 59 agreement with the results recently attained on entirely different lines of research, and will, moreover, contribute to render them intelligible. First let us face the problem of the specific interdependent localiza- tion of the principal tissues and organs of organic individuals. As re- gards this highly important question concerning the structural localiza- tion and unity of composition of living animal beings, I will quote the solution I ventured to advance as applied to inferior organism. This i^olution will be found to flow naturally from the constitution and the activities of the living substance, as explained in the former section. The quotation is again from Mind, No. xx, 1880. "Here is a clear- cut protoplasmic ovoid flowing evenly along, straight across the field of the microscope. We will not let it slide by without closely scrutinizing its activities; for, after closely examining them, it will seem as if this morphologically undifferentiated organism had been made on purpose to reveal to us the secret of tissue-formation. It embodies all the es- sential traits of organization, but organization not yet structural ly_ jSxed. Like our Paramtecium it also maintains a definite shape. It is bilaterally symmetrical. It has anjpral and an ahoyal pole, an incip- ient integument and contractu layer, a digesting substance, a depurative vesicle peculiarly situated. It takes food in only in front, retains it until digested in the center of the body, and eventually evacuates the residue at the aboral pole. There can be no doubt it constitutes a complete organism with definitely determined positions of all its parts. / Yet it can be readily ascertained that it consists, nevertheless, of noth- ing but a fluent mass of molecularly coherent protoplasm. We have here before us a single unit of living substance, fluent through and through, and exhibiting, notwithstanding, a strictly localized distribu- tion of organic divisions and functions ; we have before us aLjjyino;^ vor- tex, maintaining itself, and advancing head-foremost through space." '^All the differently functioning regions of our vital vortex gain their peculiarities merely from the special position which they occupy in the chemical cycle that constitutes protoplasm. We have here, indeed, es- sentially one and the same substance performing all the sundry organic offices ; but it is by no means one and the same substance in one and the same state of efficiency. It is a complex chemical circuit that gives rise to the definite location of all the chief dift'erentiations of the or- ganism; and it is the same substance at the different stages of this its chemical circuit, which by means of its specifically changing relations, becomes in turn the seat of all the main performances of vitality." "The fundamental features of organization assumed by the living sub- stance are the result of the same chemical cycle by which this very sub- stance is itself formed and sustained." At trie time this view was ad- vanced such a protoplasmic individual was believed to be throughout composed of an aggregate of equal molecules ; and each part of it was held to be indifferently capable of performing all vital functions. Visibly the living substance, when assuming the shape of a single pro- toplasmic process or pseudopodium, forms then by force of its chemic- 60 . Vitality and Organization of Protoplasm. ally cumulating reintegration and its definite relations to the medium, a self-rounded organism, performing all essential vital functions in in- teraction with the medium, and having the functional differentiations and localizations of organic structure determined in consequence of it. ^ The problem of structural differentiation and localization can there- \ fore not be statically solved, having regard only to the morphological I juxtaposition and conjectured interactions of separately formed parts. ; Under such a supposition the formative agenices remain hopelessly un- ! intelligible. For organic shaping can nowise naturally result from a mosaic-like arrangement of separate units. It is obviously a unitary dynamic j^rocess, whose indivisible vital activity involves the construc- tion of the organism as a whole. It evinces, as Driescli would say, the autonomy of vitalj^^henomena. "The living substance has to be looked upon as a_chemically cumulating vortex, whose foremost and highest region comes into active "coiitact "with the surrounding medium, suffering thereby functional disintegra- tion; and whose basal substance, in the case under consideration, enters into direct assimilative relations of reintegration with nutritive ma- terial. The continuously evolting living substance increases in chem- ical comj^lexity the further it gets advanced from the region where nu- triment is directly elaborated. The foremost and outermost regions of the organism, its apex and circumference, are, in consequence, the chemically highest portions of the protoplasmic unit. Its headmost portion represents, in fact, the consummation of all the vital labor per- formed within the organism. And the outer surface constitutes a chemically graduated substance, of which each succeeding zone is dif- ferent in quality and responsive reaction from the one preceding it in position. In the former section it was found, as repeatedly stated, that what was called the dynamical interaction with the medium, constitutes the Ijighest function of the protoplasmic individual, and that it necessarily involves nutrition and depuration, which three indivisible processes un- derly their vitality and govern their organization. This being dem- onstrably the case in lower forms of life, it is by no means visionary, or too bold a stretch of scientific imagination to look upon the com- plex configuration of Metazoa as the visible structural elaboration of these three indivisible vital activities: functional interaction with the sundry dynamical influences of the medium inciting the gradual de- velopment of ectodermic structures; interaction with the nutritive ma- terial resulting in the development of entodermic structures ; and cor- responding structural development of depurative organs taking place in direct or indirect interaction with atmospheric oxygen ; the entire organic development being essentially induced and controlled by the dynamical life of outside relations carried on by the ectodermic struc- tures, by which motor activities play a prominent part. The problem of structural differentiation and localization in its gen- eral features fnds its solution in these results arrived at by the study Vitality and Organization of Frotoplasm. 61 of protoplasmic individuals of a low order of development. The labor- ious task remains to apply it in detail to successively higher forms of life, whereby accurate inferences from comparative anatomy and com- parative ontogeny may possibly yield the desired knowledge; for, of course, the problem is at the bottom one of phyletic evolution. Xot to overrate the kind of information we have been here gathering from directly observable phenomena, it is well to remind ourselves here again that chemical constitution with its specific configurations and most specific" modes of reaction is a creative datum transcending, ,scieii- tmq explanation. We can not explain why and how a complex of sim- ple elements of a few well known inorganic substances come to be en- dowed with the potential power of forming by intricate modes of com- bination with one another an innumerable host of complex organic substances, each specifically distinguished from others, often by aston- ishingly different properties, as is strikingly exemplified by the hydro- carbons. It stands to reason that the infinitely more complex and mani- fold constitution of what is collectively called protoplasm or the living . substance, phyletically elaborated during" ages upon ages of interaction with the various influences of the medium; it stands to reason that this ! phyletic substance will display correspondingly complex and developed modes of specific reaction. The combining and reacting potencies of what we perceive as protoplasm are intrinsic properties of its chemical constitution, though incited to activity, and influenced- in taking special developmental directions by the interacting agencies of the medium. To add to our explanatory perplexities we have, furthermore, to acknowl- edge that all these wonders of chemical constitution and reaction are only symbolically revealed in terms of our own sensorial perception, and especially of our visual awareness. However, the relation of con- sciousness to perceptible nature is an epistemological problem only to be indicated, but not discussed in this biological treatise. GER:\I-rLASM AXD ITS ORGANIZATIOX. From numerous and varied experiments with eggs of EchinidiB Driesch felt justified in concluding that egg-plasm possesses normally the character of an organization; but that, after disturbances had upset the normally organized arrangement, every not too minute portion or amount of egg-plasm retained, nevertheless, the power to reproduce the complete, though proportionally reduced form of the embryo. It follows therefrom, in opposition to the theory of a preformed mosaic of definite germinal units, that not only "segmentation mosaic need not be mosaic of potentialities," but also that distinct potentialities do not inhere in specific germinal units. This astonishing discovery is of ut^ most importance to the science of life. It carries with it the strongest proof of the utter futility of trying to explain vital phenomena in ac- cordance with purely mechanical principles. And it reveals also the inept superficiality of the mere mechanistic view of organization. It renders certain, on the other hand, that not only germs as a whole, but 62 Titaliiy and Organization of Protoplasm. also fragments of germs^ are endowed ^Yith an intrinsic formative power capable of reconstituting specific tissues and forms, which are organized down to their minutest component parts, and throughout alive to their innermost core. This formative and vitalizing feat on the part of small fragments of germ-plasm surpasses incommensurably anything that mere mechanical actuation can possibly accomplish, and mere mechani- cal arrangement can bring about. It has been shown that only by recognizing reproductive plasm to be in every instance a specific cJiemical fragment of a specific chemical whole, can we gain a scientific insight into this most wonderful of all occurrences in perceptible nature; the faithful reproduction of a defi- nitely predetermined and intricately constructed organism from a min- ute bit of morphologically all but homegenous plasm. By means of ontogenetic experiments of the same kind, it was also found that the nucleus, to which the entire formative potency had been ascribed, does not really play any leading part in this formative process. This conclusion is likewise of great importance to a right understanding of ontogenetic processes. It may have been considered strange, that in the section on "Vitality" no notice was taken of the nucleus, which is still considered by many observers to be of paramount importance in the actuation of vital phenomena. The discussion of the part it is taking in vital processes has, however, been intentionally reserved for this and other pertinent occasions. The study of the self-division of certain Protozoa forced upon the present writer^ likewise the conclusion that the nucleus is playing only a subordinate part in vital and formative processes. In reference to the distinctly visible, clearly outlined nucleus of gigantic amoeba, I remarked in the Jenasche Vieteljahrschrift fur Naturwissenschaft, 1882, p. 689 : "As a self-rounded, sharj^ly outlined granular body the nucleus of the amoeeba is pushed and rolled from place to place during the creature's changing movements, and is forced now in front, now behind, and again into any other position." "No forrnative organic process determines for it from moment to moment its specific position and form. It is not an integrant constituent of the continuous cycle of activities to which the life of protoplasm owes its existence. It is a persistently established accessory organ, whose gen- eral function is not yet ascertained, but which presumably consists in the absorption of oxygen." Sundry experiments performed since the above was written seem to confirm the conjecture that the function of the nucleus is intimately connected with the indispensable process of oxydation. To this con- clusion Loeb has arrived, as explained in the Archiv fur Entzwicklungs- Mechanic. 1899, p. 689. Pieces of non-nucleated living substance quickly disintegrate, while pieces containing oxygen-absorbing chloro- phyll retain their vitality for a long time. The fact that blood-cor- puscles are absorbers of oxygen seemed to me also to favor the con- jecture I had formed. For blood-corpuscles originate from nuclei de- tached from the epithelium of lymphatic glands and form kindred kinds Vitality and Organization of Protoplasm. 63 of epithelium. Neither white nor red blood -corpuscles are autonomous cellular beings, and as siich really independently alive. The amoeboid motions of the -wdiitc corpuscles are not genuine vital motions. To this conclusion I arrived long ago on the strength of numerous observations and experiments.* This may suffice at present to characterize my view of the functional import of the nucleus. As to the specific role attrib- uted to it in mitotic division, it will be examined when fertilization comes to be discussed. The principal ontogenetic results gained by experiments with the eggs of many kinds of organic beings, and no doubt essentially applica- ble to ontogenetic evolution in general, can, I think, be deduced from the recognition of the cardinal fact, the egg-plasm is a chemical frag- ment of the organism from which it is derived. A chemical fragment of the egg-plasm must necessarily possess a definite chemical constitu- tion, an intimate "molecular" organization, which strictly predeter- mines the structure of the progressive stages of ontogenetic evolution, or, what is the same thing, the stages of its chemical reintegration. But this definite normal constitution of the egg-plasm as a whole, when upset or disrupted, its complete living substance, or parts of it, suffer- ing thereby additional disintegration, necessarily falls — as has been shown to be the case with the disintegrated protoplasm in general — inttj different chemical equilibration, forming thus a new and different chem- *In a paper read before the Royal Society of London, December 20, 1866, I showed that the nuclei of various kinds of epithelium furnished under different conditions what were known as white bloodcorpuscles, granulative corpuscles, mucous corpuscles, and puscorpuscles. And on the strength of these and other observations I said in "Mind," No. XX, p. 486 : "As regards the autonomous vitality of organic elements, the white bloodcorpuscles have had chief stress laid on them. The white bloodcorpuscles of which red bloodcorpuscles are trans- formations, perform amoeboid movements. What more striking proof of the separate vitality of each single cell could be found, than the displaj'^ of motility on the part of its protoplasm? Nevertheless these movements are not vital movements, but merely the eflfeet of a chemical metamosphosis of protoplasm. Yoimg infusoria under unfavorable conditions are sometimes unable to main- tain their surface-equilibration. They are then transformed into amoeboid be- ings, the substance of which gradually declines in molecular constitution till, at last, all activity ceases. A white bloodcorpuscle forms originally an inte- grant part of an organic tissue. It is then detached from it, and left to attain chemical equilibration in a new and constantly changing medium. In some an- nelids the inner surface of the entoderm, the surface forming one of the walls of the perivisceral cavity, is seen during digestion to become densely crowded with large refractive granules. Irregular flakes composed of such granules held together by a viscid hyaline protoplasm, detach themselves and float about in the perivisceral cavity, constituting primitive bloodcurpuscles, and displaying amoeboid movements. This I have watched numbers of times." "Tlie Idood- corpuscle does not maintain its structural integrity, on the contrary, it is trans- formed from a lymph-corpuscle into a red bloodcorpuscle, and, after having spent its store of chemical efficacy, is soon eliminated as effete matter. Its amoeboid movements are not due to any vital play with the medium, but are simply move- ments accompanying its career of chemical transformation. In pus-corpuscles even the myeline-nature of the projections can be sometimes detected with the help of the polariscope. The most perfect movements of the kind I have ever witnessed were displayed by pus artificially derived from the epithelium of an eye macerated in serum for forty-eight hours at a temperature of 96 F. 64 TitaJiiy and Organization of Protoplasm. ical fragment. And this is also found to be capable of reintegrating in its own way the structure and form of the embryo as a whole. The new fragment possesses no longer the same organic arrangement of the egg-plasm as a whole; but, being of a lower chemical order, it takes up the work of reintegrating the embryo at a less differentiated stage of its structural reconstitution than had been the case with the normal egg- plasm. • This hypothetical interpretation, unlike the fanciful conception of aggregational and mechanical views^ flows consistently from the ascer- tained nature of the living substance, as explained in the former section. It is confirmed by the different stages of chemical or structural develop- ment found established in the egg-plasm of different organisms. In some organisms their egg-plasm consists of a less disintegrated or rather higher integrated fragment than in others, and represents therefore a more advanced and firmer stage of structural development or "matura- tion," evincing itself in a more definitely and solidly differentiated or- ganization, or so-called mosaic-like arrangement. The interpretation here ventured of these striking and most instruc- tive ontogenetic phenomena, revealed by means of experiments with egg-plasms, is signally corroborated by Morgan's experiment with the substance of the living half blastomere of the egg of frogs, whose ad- joining partner had been killed. Left in its normal position the living blastomere developed into a half-embryo. By disturbing the "mole- cular" or structural arrangement of its substance through reversion of the egg, it developed an entire embryo of reduced size. Here the blas- tomere possesses obviously at first a definite unilateral organization, de- rived from the bilateral organization of the egg-plasm as a whole. Its definite chemical constitution, representing only one-half of a normally established ontogenetic germ, being upset, its living substance becoming thereby further disintegrated, retains nevertheless its character of being a fragment of the entire organism of which it is derived, and reinte- grates itself as such, not to a half, but to an entire embryo. It forms a new germ at a lower chemical level, involving potentially complete formative potency. Even small artificially severed portions of egg- plasm, at different stages of its ontogenetic evolution, retain the power of reproducing not the mere structure of the plasm from which they were immediately severed, but the structure and form of the entire em- bryo; and their living substance must therefore reconstitute itself a chemical fragment of the entire organism, of which it then proves to be a reproductive germ. In a general way it may be asserted, that the higher the stage of chem- ical integration, or ontogenetic evolution the egg-plasm represents in relation to the whole embryo it is destined to reproduce, and also the higher the organism of which it is derived stands in the scale of animal development, the less readily will fragments of such egg-plasm, or frag- ments of such organisms reconstitute themselves into totipotent germs. In order t]]at fragments may become totipotent, their living substance Vitality and Organization of Protoplasm. 65 has first chemically to reorder itself, so as to form- a germ representing an initial stage of ontogenetic evolution. This reduction of artificial fragm.ents to germinal totipotence occurs more readily when they are derived from lower stages of ontogenetic and phylogenetic evolution. In Infusoria, during the process of their self-division, the formation of two exceedingly minute totipotent germs or centers of reproduction, and the gradual reintegration therefrom of complete adult organisms, can be observed from beginning to end. The more developed the organism from which the fragment is de- rived, the more it is found to resist reduction into ontogenetic totipo- tence. And the more will it possess only the power of regenerating the part or the tissue of which it is an immediate fragment. Fragments of highly developed tissues, or even of entire organs, when left attached after almost complete loss or extirpation of the respective tissue or organ, may reproduce or regenerate the same. An extreme instance of this circumscribed and localized regenerative power in an animal high in the scale of development is afforded by the remarkable regenerative processes observed in Triton. Gus. Wolff's startling discovery of the regeneration of the lens from the iris, and of the injured iris itself, not from the injured surface, but by a deep-seated formative process, may possibly find their explanation in such localized and partial regenerative potency. In certain worms such localized and partial regeneration is plainly exemplified when, for instance, whole segments with all their tissues are regeneratively intercalated; or, in other cases, when after partial resection some internal organ is regenerated. Yet, though local- ized and partial, these regenerated tissues or organs are incorporated as integrant constituents of the entire organism. The formative process is still under the control of the whole. It may be conjectured as highly probably that this power of localized regeneration is a phenomenon in- dicative of such localized germinative processes occurring normally during the ontogenetic evolution of separate tissues, complicating thereby the epigenetic process, without interfering with the general pre- determined tendency of reproducing the organism as a formative whole. And it may possibly also help to account for the reduced size of repro- duced structures and forms, when only a reduced amount of assimila- tive material is given for chemical reintegration. Normal germ-plasm is never derived from highly differentiated tis- sues, never from muscles, nerves or sensory organs. This fact sufficiently refutes, if such refutation were necessary, the fanciful notion of some biologists, that the successively differentiated cell-generations of onto- genetic evolution represent "alternate generations." As regards the definitely discernible structural differentiations of the evolving germ-plasm, they start into perceptible existence more or less early and more or less distinctly, probably in proportion as the germ- plasm is representing a higher or lower stage of ontogenetic elaboration or "maturation," and in proportion as the adult organism in the course of reproduction is itself of a higher or lower order in the scale of 66 Vitality and Oi-ganization of Protoplasm. phyletic evolution, and in proportion, moreover, as the embryo repre-- sents a more or less advanced stage towards the complete reproduction of the adult organism. The germ-plasm itself must at every stage of its evolution necessarily possess a more or less complex chemical organi- zation in proportion as it is derived from a more or less complexly de- veloped organism, , To our vision ontogenetic evolution assumes the aspect of a process giving rise to different definitely grouped parts of the evolving sub- stance, and it takes a definitely regulated course within the portion of our field of vision occupied by the developing substance. Our conclu- sions regarding the specific potencies actuating these visible changes have to be inferred from what we see arising here and there within the sphere of the evolving plasm. However accurate our observations and descriptions of such spatial changes may be, it is clear that the infer- ences and interpretations based upon them, regarding the agencies actuating the changes, and also regarding the interdependence of the changes seen to take place in different parts of the evolving plasm; that these inferences and interpretations are of a different explanatory order from that of mere description. To the extremely difficult solution of these ontogenetic questions of special potencies, and causal dependence of localized changes, experimental ontology is supplying the most effi- cient and instructive means. But it must not be forgotten, that the final, predetermined result and outcome of all the divers and complex changes is the exact reproduction of the adult organism from which the germ-plasm was derived. The sundry divers changes form part of one and the same ontogenetic pro- cess. Or as Driesch more specifically expresses it : "Despite relative self-differentiations something unitary is achieved." The entire onto- genetic evolution which we see running its course in space and time with such intricate formative manifestations is essentially a unitary pro- cess, predetermined in its minutest details in the specific chemical con- stitution and in the chemical potencies of the germ-plasm ; attaining its final goal in the definite organization of the reproduced adult organ- ism as an indiscerptible whole. There is here at work no sort of struggle for supremacy of separate elementary units, and no automatic co-opera- tion of the same. From its initial stage to its completion the onto- genetic process consists in the harmonious, gradual reintegration of a specific chemical fragment under complemental assimilation, until it has effected the reconstitution of the whole of which it is a fragment; and which whole is then visually revealed to us as the complex adult organism. If a morphologically undifferentiated fragment of the egg of a frog can reproduce an entire, highly differentiated, embryo, it is almost self-evident, that, in what may be rightly called the chemical constitu- tion of the egg-plasm, must lie the power to evolve the eminently com- plex structure and form of the adult frog; that, therefore, this emi- nently complex structure and form represents to us the perceptible out- Vitality and Organization of Protoplasm. 67 come of the chemical evolution; that, in fact, the structure and form of organisms is the perceptible manifestation of a unitary, though mar- velously complex, composition and activity, scientifically expressible in terms of chemical experience. In the section on Vitality it has been shoAvn that the living substance, out of which all organisms are formed, owes its vitality to a process of alternate disintegration and reintegration, involving all essential vital functions. It has been furthermore shown, that the fundamental structural and functional differentiations of animal beings originate through the very same cycle of chemical activities, which imparts to the compound called protoplasm its vitality, and causes it to be a living sub- stance. And it has long been known that minute artificial fragments of so-called unicellular organisms, whose undeniably unbroken contin- uity of living substance is evidently of chemical consistency ; that such chemical fragments have power to reintegrate the highly complex structure and form of certain Protozoa, which process we can watch in its fluently coherent operation. Considering all these facts it certainly lies near to conclude, without overstepping the limits of scientifically justi- fied inference, that organic beings, consisting as they do of phyletically elaborated living substance, and possessing whatever complexity of structure and form, are likewise essentially chemical wholes, ontogenet- ically reproducible from chemical fragments. Confronted by the results of experimental ontogeny and experimental regeneration, the inference is inevitable, that the reproductive germs or fragm.ents mu&t either possess as such intrinsic formative powers of their own ; or that, on the contrary, they are merely the vehicle and raw material of a formative power not inherent in themselves, but moulding and evolving them from out a trancendent order of existence into the nevertheless predetermined structure and form of the organism from which they were derived. The first inference, that of inherent forma- tive power, becomes scientifically intelligible when the germs or frag- ments are recognized as being specific chemical fragments of a specific chemical whole. Though what we call chemical composition, activity and affinity are terms for efficiencies, which are only symbolically re- vealed as sensorial phenomena within our individual consciousness, scientific explanation consists in gaining an understanding of what is thus symbolically revealed. The alternate inference, that of a trans- cendent moulding and evolving power, is incommensurable with scientific thought. It transfers ontogenetic and regenerative actuation to a wholly hypothetical sphere of existence and efficiency, whose doings are superimposed upon the visibly evolving substance, which can serve it then only as inert raw-material. It is obvious that this means the assump- tion of a vital force of the old metaphysical kind. In accordance with the views here advocated a few words concerning the vexed contention of evolution versus epigenesis may not be out of place. Ontogenetic evolution, the evolution of a germ into an adult organism, may rightly be called evolution in the strict sense of the term. 68 Tiiality and Organization of Protoplasm. in so far as the constitution of the adult organism is rigorously predeter- mined in the chemical constitution of the germ. But the adult organ- ism is nowise structuarly pre-established in the germ in the sense of Bonnet, Haller, Eoux, Weismann, and their more or less faithful fol- lowers; nowise in the sense of the old and new theory of structural pre- formation. It is not as Eoux declares the merging into visibility of latent pre-existing differences. It is the merging into visibility of newly arising differences. Ontogenetic development takes place through such epigenesis as advocated by Wolff and Baer; epigenesis, namelj'', in the sense that morphological structures merge into visible existence as out. and out new formations, one stage of structural development serving as foundation for the next stage. The development of the germ into an adult organism is chemically evolutional, but structurally or morphologically epigenetic. In ontogenetic evolution the successive stages of chemical reintegration, though evolutionally predetermined, represents a forma- tive process by w^hich the structures of the adult organism are newly reproduced. True phyletic genesis consists in the complete new formation of what is being for the first time produced, and not merely generically repro- duced. Creative increments of organic development give here rise to progressively higher forms of beings, and the corresponding reproduc- tive potentialities of their germs are newly acquired, and represent not merely a pre-existing fund of previously established dispositions. SEGMENTATION. The disentanglement of the factors that condition the segmentation of the germ-plasm, and therewith the normal "prospective import" of the successive blastomeres, is no easy task. To rightly attack the prob- lem one has above all to discard the misleading notion, that what we have here before us as an e^g represents anything in the remotest degree resembling a cell, or elementary organism, as scientifically defined. The germ-plasm is nowise an autonomous elementary organism, which mul- tiplies by self-division. Its divisions are essentially a_ nianifestation of unfolding potentialities, in which all , ensuing formative, evolution is rigorously predetermined. An egg-cell, instead of being an autonomous elementary organism, represents^ on the contrary, the potential concen- tration of all the accumulated results of phyletic elaboration. This should be quite obvious without further discussion, though, strange to say, most zoologists still adhere out of traditional prejudice to the cell-theory, which has come to be highly obstructive to biological progress. But liow do tlie two first blastomeres come each potentially to repre- sent one entire half-embryo? It has been shown that the living sub- stance in its earliest fonnative manifestation, as an amoeboid projection, or so-called pseudopodium, assumes by force of its intrinsic constitution and its vital motility a symmetrically bilateral form. And when the en- tire living substance of an amoeboid being comes to constitute one single Mtaliiif and Organization of FrotopJasm. 69 such projection or pseudoiwdium steadily maintained, it clearly repre- sents a bipolar and bilateral organism. How then does it happen that in its higher stages of development this unitary bilateral constitution of the living substance becomes divided during ontogenetic evolution into two imilateral, but still interdependent halves? Here one is led to assume, that in the course of phyletic elaboration the two lateral halves of the living substance, though composing a continuous whole, have each undergone more or less independent structural development, having necessarily been separately, but under the same conditions, exposed to the same stimulating influences of the medium, with which they have stood, and are still standing in a relation of functional interaction. The separate structural elaboration of each unilateral half has here evidently come to constitute the most fundamental organic differentiation re- tained in the chemical organization of the germ-plasm, expressing itself ontogenetically in the segregation of the two first blastomeres, of which each possesses then separately the power of further self-differentiation. Bichat already recognized the bilateral duplication of organs as the essential characteristic of what he called the animal life, which is the life of the dynamical outside relations structurally embodied in the ectodermic organs. Numerous observations and experiments prove that the germ-plasm is bilaterally organized even before fertilization. Watase found that the egg of the Loligo pealii discloses already before fertilization a bilaterally symmetrical arrangement of its substance, which determines the direction of the first segmentation, and the axis of the embryo. The plasm of the egg of most insects is visibly bilat- erally arranged. In annilides and mollusks the egg-plasm has like- wise before fertilization a visible bilateral arrangement, which deter- mines the direction of the first segmentation. Driesch showed by ex- periments with the eggs of Echinus that they possess a bilateral structure before fertilization, which after fertilization determined the direction of the segmentation, and which in consequence is not due to the influence of the spermatozoon as had been asserted by some investigators. R. Hertwig, Morgan, Loeb and others by inducing through chemical means ] unfertilized eggs to undergo normal evolution, proved thereby the orig- ; inal bilateral structure of the egg-plasm. It is of paramount importance, as already stated, to recognize that the first two blastomeres can nowise be regarded as the autonomous off- spring of a self-dividing elementary organism, as demanded by the cell- theory. Self-division produces here no equal sister-cells; equal to each other, and equal to the mother-cell. On the contrary, self-division divides here a whole into two complemental halves, each representing only one lateral half of the "germ-cell" in a somewhat more advanced stage of ontogenetic evolution. They each possess laterally con'espond- ing ontogenetic potentialities, representing complemental halves of the organism to be reproduced. The two primary blastomeres segregated during ontogenetic evolution from an undivided whole, are destined conjointly to reproduce in the course of ontogeny by one and the same 70 Vitality and Organization of Protoplasm. developmental process, the unitary, indiscerptil)]e organism of which they are complemental parts. As halves of a common whole, they pan certainly not be autonomous, elementary beings, the offspring of an elementary mother-cell. This simple consideration contains, it must be again insisted /ipon as of utmost importance, inevasively the complete refutation of the cell- Ljheorj. For it is of the essence of this theory that an elementary mother- cell propogates by fissiparous division, autonomous lineal offspring of the same kind. Instead of this, all successive divisions of the egg- plasm prove to be divers interdependent, complemental parts of a strictly predetermined whole. There could be no more thorough-going disparity than here obtains between the generally accepted cell-theory and the real state of things, as unmistakably revealed by experimental ontogeny. Of whatever nature and import the more or less distinct cellular divisions of the organism may be, they are"* certainly not the autonomous lineal progeny of an eleinentary cellular being, which the cell-theory declares tKemto be. At every step of our biological interpretation we have found the cell-theory obscuring, instead of elucidating the scientific explana- tion of observable facts. On further segmentation it seems that the two different germinal layers, the ectodermic and the entodermic substance become plasmati- cally and germihally segregated. The organism to be evolved from the two primary germinal layers, as they are called, stands constitutionally in opposite relations to the surrounding medium. The ectoderm repre- sents mainly the structures that minister to the life of active outside relations, the Jife that carries on the functional play with the dyna- mical influences of the medium. Entodermic plasm, on the other hand, evolves the organs of the so-called vegetative life, which enters into direct interaction with the nutritive material furnished by the medium, and elaborates assimilable pabulum for functional restitution. Here also both layers, though more or less distinctly divided from each other, evolve their structures conjointly in subservience of the unitary purpose of reproducing the indiscerptible adult organism. As to subsequent stages of segmentation, they would seem, to judge from final results, to segregate the plasm destined to evolve the separate metameres, of which the organism is composed. Each metamere repre- sents an orig^ijiaL^Qgixl, which contains a complete structural organiza- tion of_its own, retaining it ontogenetically, though blended more ar less intimately with the unitary organization of the complex individual to be reproduced as the final aim of the entire reproductive process. The division into the prospective metamera would then be followed by the parallel evolution of the sundry structures found respectively to form^ part of them. And as regards nutritive and depurative organs they would all along concomitantly evolve in constant harmony with ectodermic organs. The obvious inference from all these ontogenetic phenomena is, that every stage and division of the eminently complex evolution, iiowever Vitality and Organization of Protoplasm. 71 separately disposed and circumscribed its spatial manifestations may appear to our vision, that it all forms, nevertheless, from start to finish, a unitary ontogenetic process, every phase of which is integrantly con- nected Avith every other. FORMATIVE STIMULATION. The specific stimuli or inciting agencies that act as inducing causes in the development of the succeeding stages of ontogenetic evolution, and which have been so diligently sought for, now in external, now in internal conditions; these inciting causes are actually found in the im- mediate conditions which give rise to gradual reintegration, and there- with to ontogenetic evolution. The presenceT namely, of specifically assimilable~material coming in contact with the living substance, at whatever stage of its disintegration, germination or fragmentation, nat- urally and necessarily acts as a specific formative stimulus, calling into activity the inherent power of £c.mtegration througji complemental as- similation. Eeeiprocal chemical attraction between the assimilating vital fragment and the assimilable material, due to their complemental jiffinitj are here evidently the actuating agencies. This interpretation flows consistently and harmoniously from the general vital properties of protoplasm, as explained in the former 3v3ction, The power of com- plemental reintegration, after more or less profound disintegration is that which essentially, constitutes protoplasm a living substance. By having gained the scientific understanding that assimilation is a process of reintegration on the part of the unitary living substance, and not a new formation of elementary units, it becomes clear that the presence of assimilable or complemental ma,terial will act upon frag- ments of the living substance as a specific and adequate stimulus or in- citing cause whereby reintegration is effected. No need here of any other specific stimuli, provided the conditions of the general medium are otherwise normal and favorable. In higher organisms morphological appearances mask to a great extent the unitary formative process. To- gain a clear idea of the far-reaching commotion of the chemical activity and its concomitant mass-movements during ontogenetic evolution, one need only closely watch the phenomena occurring, for instance, within the spherical plasm of a self-dividing Colpoda. The process, though primarily one of self-division, involves *the ontogenetic evolution of a new generation of individuals from germs derived from the parent organism. Here two and often four and more separate germinal centers start into existence within the spherical plasm, and around each the reintegrating work takes its course. It consists evi- dently in an extremely complex process of chemical assimilation and elaboration. For more or less vivid commotion of granules; more or less extensive mass-movements of plasm, with concomitant formation of larger or smaller depurative vesicles, more or less rapidly arising, dwindling and reforming, testify to the intimate chemical nature of the occurrence. The unitary substance of the plasmatic sphere is under- / 72 Vitality and Organization of Protoplasm, going transformation through and through, resulting eventually in its self-division. Each germinal center attracts, stage by stage, of its onto- genetic evolution, the requisite complemental material from the general plasmatic fund, until each developing germ has become an entire self- rounded organism, separated from the rest, not by any membrane, but by its own chemical constitution as an individuated whole. In each individuated unit a lively formative process continues its work, often involving the rotation of their entire substance. They then glide round and round one another, the direction of the rotation becoming at times reversed, and at times ceasing altogether, whilst all along the internal motion of granules at different places, and the formation of depurative vesicles, afford proof that the formative commotion is due to chemical activity. Suddenly the adjoining individuals, now fully organized, sep- arate and dart away, each to pursue life on its own account. In this case tlie separating individuals do not finally break through an inclosing membrane, as is the case in some other infusoria. No trace of a mem- brane inclosing the plasmatic sphere is visible during the formative pro- cess, and no trace of such a membrane is left after the individuals have separated. This interesting fact would seem to justify tlie inference that chemical taxis holds the segregated units together until diminish- ing in power with their increasing structural organization its attraction ceases at last altogether, allowing the completely individualized units to sever their connection. I have observed ,on other occasions similar manifestations of chemotaxis in operation between protoplasmic in- dividuals, which I was led to ascribe to complemental chemical affinity between the attracted beings. Now, is it not likely that in Metazoa similar ontogenetic commotions and mass-movement, involving the shifting of certain substances and the wandering of certain /^cells^' to different positions; may not these seem- Jng, attractions from a distance be due to essentially the same kind of chemical elaboration and assimilation, as directly witnessed in our Col- poda ? FERTILIZATION. It has been found that the unfertilized egg-plasm is already bilaterally organized, and also that artificial conditions can incite it to partheno- genetic self-evolution, whereby it undergoes the same normal segmenta- tion as it would have undergone after spermatic fertilization. This being so, what kind of specific influence on ontogenetic evolution has the fertilization of the egg? The intrusion of the spermatozoon can, of course, not be regarded as a mere incitement, which simply sets going the self-evolution of the egg-plasm, as has been actually believed by some biologists. The spermatazoon contains evidently as complete an endowment of ontogenetic efficiencies as the egg itself. The bisexual adult organism proves clearly to be a product attained by the intimate blending of male and female germ-plasm. How, then, does tlie germ-plasm of the sperm- Vitality and Organization of Protoplasm. 73 atozoon manage to become materially and potentially unified with the ,i(erm-plasm of the e^g, without upsetting the intimate specific potential constitution and bilateral arrangement possessed by the egg-plasm be- fore fertilization, which determines the formative course of ontogenetic evolution? This question gives expression to the most central and es- sential problem of bisexual ontogenetic evolution. And it may be re- garded as the stronghold of those who believe nuclear plasm to be the sole and real germ-plasm. For the head of the spermatozoon is un- deniably of nuclear origin and consistency. It represents in fact a complete nucleus. Now, if the nuclear head really carries with it all male ontogenetic potentialities, and if the nucleus of the egg, with which it combines, contains on its side all female ontogenetic poten- tialities, then, despite all contrary considerations, there is no escaping the conclusion that the rest of the fertilized egg-plasm can be only in- different raw-material at the service of the ontogenetically evolving nu- clear plasm. And in this case the alleged organization and bilateral constitution of the non-nuclear egg-plasm could be of no ontogenetic consequence. Hence to avoid this dilemma more felt than recognized, we have the elaborate theories of diversely endowed and diversely aggregated forma- tive units, assumed to compose the minute speck of nuclear plasm, nay, to compose the much more minute chromosome. To these hypothetical, ultra-microscopical elements would then fall the stupendous task of structurally reproducing from out their invisible retreat the compara- tively enormous bulk of the adult organism. For, as just stated, under the assumption of formative chromatic elements it is logically inadmis- sible to attribute to somatic plasm any other office than that of supply- ing constructive raw-material to the chromatic germs. They alone would have to construct the adult organism, out and out, by means of their own self-divisions or spontaneous multiplications, which proliferation would have to occur at an inconceivably prodigious rate, resulting in an organ- ism consisting of nothing but chromatic units, miraculously aggregated so as to constitute the tissues and the form of the adult organism, and to actuate its many interdependent functions. It is true, the visible specific divisions and sections of chromosomes, with their definite, numerically regulated distribution, and their specific mode of deployment, afford a tempting ground-work whereupon to erect theories of heredity and ontogeny. But the nuclear, aggregational hypothesis of vital and ontogenetic potencies possessed singly by an in- credible host of invisible elementary units ; such an hypothesis is directly contradicted by the very nature of the living substance out of which all organisms are formed. And it is refuted by the non-participation of the nucleus in all essential vital manifestations and formative processes. The distinctly circumscribed nucleus of some amoeba, for instance, take, as already stated, no active part in the vital manifestations of the im- mensely larger bulk of non-nuclear plasm, nor in its formative phe- nomena. The cvcle of chemical activities which sives rise to the vital- 74 Vitality and Organizaiion of Protoplasm. ity and formation of protoplasm, is operative solely in the non-nuclear substance, and the nucleus itself performs only an accessory function in the vitalizing and formative process, however indispensable this acces- sory function may be. The nucleus can here, consequently, nowise be regarded as the exclusive bearer of vital and formative efficiencies. In Metazoa the nuclear chromatin divides into exactly ec|ual parts, while the "cells," into which it equally enters, divide into heterogeneous progeny. The chromatic substance is therefore not accountable for the cellular differentiations. The hypothesis of the qualitatively unequal di- vision of chromatic plasm, which underlies Eoux's and Weismann's view of heredity and ontogeny, and which is seemingly supported by the formation of half-embryos from each of the two first blastomeres^ .«3rtiis view is sufficiently disj^osed of by the repeatedly and amply confirmed demonstration of the ontogenetic totipotence of the plasm of each blas- tomere. As the same nucleus is here present in both cases, in the forma- tion of the half-embryo, and in the formation of the whole embryo by one and the same reproductive plasm, it is evident that the formative efficiency resides, not in the nuclear, but in the non-nuclear plasm. This is likewise proved in Morgan's experiment with the eggs of frogs, which, after one of the two blastomeres had l^een killed, the living blastomere formed whole embryos when the position of the egg had been reversd, but half-embryos when left in position. Here also the nucleus is in both cases the same, and can, therefore, have no direct influence on the form- ative process. Di^ch showed that a normally formed embryo is produced where during segmentation the nuclei of the blastomeres are by means of pres- sure shifted into entirely different positions in the aggregate mass of protoplasm. This likewise proves that the nucleus exerts no formative influence upon ontogenetic evolution. Xon-nucleated pieces of the fer- tilized blastula of Echinidse have been found to develop into plutei.. This is a further striking confirmation of the passive part played by the nucleus in ontogenetic evolution. Townsend found that non- nucleated plasm is capable of forming in plants a cell-wall when it is merely connected Avith a nucleated cell by a filament of protoplasm passing through the wall of this cell. This also shows that the non- nuclear plasm is the real formative agent. Moreover, it has to be insisted upon as essential in making way for a correct interpretation of ontogenetic evolution, that even if the con- tinuity and immortality of chromatic plasm as exclusive bearer of the formative potency be for argument's sake, granted, then the entire adult organism, in every one of its structurally differentiated parts, would really consist of nothing but self-multiplied chromatic units. For so- matic plasm, despite the assumed self-multiplication of its own con- stituent units or biophores, would neverthelesis only serve as building material, or rather only as so miich nutritive material, to the formative units or biophores of the chromosomes, which would then as such con- stitute the entire organism. The special group of chromatic germinal Vitality and Organization of Protoplasm. 75 units, called '^determinants'' by Weismann, wliose biophores arc sup- posed at the right moment and at the exact stage of development to scatter among the somatic biopliors as formative germs, and to deter- mine the specific differentiation of the cellular substance; these deter- mining biophores could accomplish this wonderful feat only by assimil- ating the inditferent biophores of the somatic or morpho-plasm, using them for their own self-multiplication, or in plain M'ords by bodily de- vouring them.* The sole alternative here would be, that the formative influences of the chromatic germs is due to an inscrutable, wholly magi- cal power, by which they determine the structural differentiations by their mere presence and contact. To endow in this manner mere hypo- thetical beings with an all-efficient, utterly mysterious power is clearly to beg the entire question. As early as 1861 Lionel Beal advanced a nuclear theory of structural formation, and bravely drew its consistent conclusions. Eelying on tincture of carmine as his principal means of research, he came to look upon all somatic structure as formed of lifeless substance secreted and fabricated by nuclear plasm as exclusive life-bearer and formative agent. And he did not shrink to declare even muscle and nerve to be such life- less fabricates. This monstrous conclusion proves once more to what extreme positions false premises will blindly drive, not only conceptual philosophers, but also close observers of natural phenomena. The refutation of the nuclear germ-plasm theory flows, indeed, directly from the nature of the living substance, and its visible vital manifestations. Yet, despite all these weighty considerations, based on actual facts, if the nuclear head of the spermatozoon can be proved to be the real and exclusive bearer of the male characteristics, then no ever so plausible an array of objections could invalidate the conclusion, that- it is after all the nuclear plasm which is endowed with specific formative powers, governing and directing ontogenetic evolution. Highly instructive observations of Boveri, and also of Wilson and Mathews, confirmed by many other investigators, prove that it is not the nuclear head of the spermatozoon which is the real bearer of the forma- tive potencies, but its medial portion known to be of non-nuclear origin y and import. As early as 1888 Boveri** described an occurrence that took place in an egg of Echinus, which of itself affords strong evidence that the non-nuclear, medial part of the spermatozoon is its real actively formative constituent. Here the medial part, in which the two cen- trosomes had formed, became completely severed from the nuclear head, proceeding with the astropheres far in advance on its course into the interior of the egg. And though no union of the spermatic nucleus with the nucleus of the egg occurred, the segmentation of the egg-plasm began to take its normal course. The spermatic nucleus, which event- *See "Molecular Theories of Organic Reproduction,'' Pro. Texas Acad. Sci- ence, 1895. **"ZelIenstudien," January, 1888, "Uber Partielle BeliucUtung Sitz, Ber. Ges-Morph. Pliys. B 4, Miinchen. 76 Vitality and Organization of Protoplasm. I ually became inclosed in one of the blastonieres, coalesced with its nu- 1 cleus. Segmentation was thus nowise influenced by the non-participa- tion of the spermatic nucleus, and the non-nuclear portion of the sperm- atozoon proved to be here the active agent in the bisexual ontogenetic process. Similar occurrences were witnessed by Teichmann (a). And numerous observations have confirmed in many classes of animals that the formatively active portion of the spermatozoon, the portion in which the centrosomes arise, and around which the astrospheres form, is the medial, non-nuclear portion. ■ This agrees entirely with the fact, that in mitotic division in general the process starts and is actively governed ^ by extra-nuclear centrosomes. Important to the contention here dwelt upon is the observation of Wilson & Mathews (b) and others, confirmed as occurring in all classes of animals examined; the observation, namely, that after entrance into the egg the spermatozoon turns completely round, so that the head comes to face the circumference of the egg, whilst its base or medial portion develops under granular commotion the centrosomes with their astrospheres, and penetrates in this position under constant activity into the interior of the egg-plasm, proving thereby that the non-nuclear, medial portion of the spermatozoon is the real bearer of vital and form- ative activities, E, Hertwig, v. Erlanger and others have come to the conclusion that the medial part of the spermatozoon and the developed *C centrosomes have to be considered as essentially identical in substance. And this really means that the formative process starting around the centrosomes involves the entire medial plasm, while it is gradually in- volving all non-nuclear egg-plasm, and finally also all nuclear plasm. The experiments on segmentation and development of artificially fertilized portions of egg-plasms initiated by E. and 0. Hertwig and con- tinued by Boveri, Morgan, Ziegler, Delage and others go likewise to show that the centrosomes have power without the aid of the nucleus to actuate and control the process which gives rise to segmentation. Boveri found, moreover, the non-nuclear portions of the egg-plasm of Echinus in which a spermatozoon had penetrated undergo segmentation solely under the influence of the activity of the centrosomes without fhe aid of nuclear chromatic substance whatever. And Ziegler* ob- served that in a normally fertilized egg the entire nuclear substance of both united nuclei remained confined in one of the blastomeres, whilst in the other blastomere there remained only the corresponding centro- / some with its astrosphere. Thereupon further segmentation took place a. Ueber Furehimg Befruchteter Seeigeleier ohne Betheiligung des Sponiui- kerns," Jenaische Zeitschrift fiir Naturwiszensehaft, B. 37, 1902. b. "Maturation, fertilization and polarity in the Echinoderni egg. Journ. Morph., V, 1895. *Furch\ing ohne Chromosomen. Arch fiir Enter. Mech B, 1898. Living far away from any public biological library, I have not been in a position to verify all quotations from the original papers, but relied in many of them on Korsclielt and Ileider's splendid "Lehrbiich," 1893. TiiaUty and' Organizaiion of Protoplasm. 77 in the non-nucleated blastomere without tlie presence, and therefore without the aid of any nuclear or chromatic substance. ^ All these manifold and numerous observations and experiments go to prove that the non-nuclear plasm is the real l)earer of the vital activi- ties and potentialities. '^ Conclusions drawn from appearances found in fixed and tinted spec- imens, however instructive, are apt to lead investigators to interpret flowing vital phenemena morphologically and mechanically, instead of looking upon them as specific chemical processes, of which the changing morphological appearances are incidental, though definitely disposed, perceptible expressions. Of course, it is from these visible appearances that we have to infer what is really happening. But we have to be careful to regard them simply as mass-manifestations of a process at work among the intimate, ultra-visible constituents of the vitally chang- ing substance. The entire organism, in all its living parts, down to the very core, is in constant vftal commotion, and repres.ents essentially a synthetic chemicaLlaboratory in ceaseless activity. It is not, as has been long believed, essentially a mechanical apparatus, whose wheel- work is made to run by the burning of food-material. This caution of not mistaking morphological appearances for stable machine-like structures, or for static chemical compounds, has to be especially borne in mind in interpreting the process of mitotic division, and above all that of fertilization and its accompanying morphological appearances. Here it is safe again to rely in great measure on what can be so readily and so clearly observed in the self -division of suitable Infusoria, the purport of which is likewise the ontogenetic evolution or reproduction of new individuals. I have in a general way described the morphological signs of the exceedingly complex chemical activity at work during the comparatively elementary case of reproduction taking place in Colpoda. In the reproduction of highly complex organisms we have to expect, even in parthenogenetic, and all the jnore in bisexual re- production, correspondingly complex manifestations of the ontogenetic process. But here also reproduction of the adult organism can start only from germs, which are specific chemical fragments of the organism from which they are derived, and which they are destined to reproduce. This, I think, has been sufficiently proved, and seems indeed quite obvious. Now as regards what really happens during fertilization in Metazoa, starting with fully matured male and female germ-plasm, and leaving out of consideration the preceding .phenomena of their maturation, I believe that Boveri's observations and views, supplemented by those of Wilson, and confirmed by a great number of investigators, as applying to many kinds of animals ; that these views can be taken as a solid founda- tion for the understanding of what really occurs during fertilization. After the matured spermatozoon has entered the matured egg, we know for certain that the egg-plasm itself has a definitely organized, bilateral structure; and we know that it is the medial, non-nuclear por- tion of the spermatozoon which is the active agent in fertilization. We 78 Vitality and Organization of Protoplasm. know, furthermore, that after fertilization has been accomplished the fertilized egg-plasm is found to be again bilaterally organized, and on its way to divide into two unilateral halves, represented by the two first blastomeres. The final result of the entire ontogenetic process proves that an intimate interblending of male and female germ-plasms has been somehow achieved during fertilization. When and how does this interblending of the two plasms take place? The medial part of the spermatozoon in contact with natural egg- plasms is seen to divide, and to form two centrosomes from which the fertilizing activity starts, manifesting itself in granular commotion and formation of atrospheres extending more and more deeply into the egg- plasm, involving more and more of it in the bisexual transformation. The matured egg-plasm proving at the beginning of the process to be bilaterally organized, it is not far-fetched to conjecture that the sperm- plasm, embodied in the matured medial part of the spermatozoon is like- wise bilaterally organized, and that its division into two centrosomes is really a division into the unilateral halves. This, indeed, becomes finally evident, as the result of the fertilizing transformation; and concomitant blending of female with male plasm, which takes place around the cen- trosomes of the medial portion of the spermatozoon ; as this result proves to be actually the formation of the two first bisexual and unilateral blastomers. Centrosomes have always to be considered germinal centers, and the formative activity around them as one of gradual reintegration towards the reproduction of the adult organism. Centrosomes may arise in pro- toplasmic beings under whatever conditions go to favor the origination of new formative centers; and they may dissolve again when their sub- stance becomes assimilated by stronger formative activities than their own. This has been proved by various experiments, such as those of Morgan after the application of solutions of salt. In normal forma- tive processes, however, the number and localization of centrosomes is definitely predetermined. It remains still unexplained how the definitely organized egg-plasm can come to be intimately interblended with male-plasm, as is the case in bisexual reproduction. How can a definitely organized structure blend with another definitely organized structure without both losing their definite organization? This is a problem inexplicable by any me- chanical and aggregational theory. It has been shown that all attempts in that direction have necessarily failed, and that we are face to face with a specific vital activity, which would have remained utterly enigmatic had not experimental ontogeny furnished us with data that essentially assist its understanding. For it has been experimentally proved that the definite bilateral organization of egg-plasm being upset, all parts or fragments of it become totipotent germs, capable of reproducing entire embryos. In fertilization it is egg-plasm tliat has become totipotent in all its parts after its bilateral organization has been upset by the in- fluence of the spermatozoon ; it is this totipotent plasm that enters into VilalUij and Orgdnizalion of Protoplasm. 79 the bisexually re^titlltive process, started and governed by the two cen- trosomes of the sperm-plasm. At each stage of its evolution the sperm- plasm assimilates congruous egg-plasm, the process ending in the for- mation of the two bisexual and unilaterally potential blastomeres. The interpretation of fertilization here oll'ered flows likewise con- sistently from the nature of the living substance, as positively demon- strated in the first section. It has to be added, that, as in normal and artificial parthenogenesis, the two first blastomeres form around germi- nal centrosomes arising within egg-plasms, it seems that even in some cases of fertilization the egg-plasm takes the lead in the bisexually blending and reproductive process. This appears to have been the case in Wheeler's observation of what takes place during fertilization of Myzostoma. And it may possibly happen more frequently than at present supposed. If this were found to be the case, it might suggest a scientific explanation of sex-determination. Indeed there is no theo- retical objection to egg-plasm-activity taking at times the lead in the process of fertilization and ontogenetic evolution, as it is otherwise so readily induced to do so in parthenogenetic self-evolution. Though this suggestion is supported by various experiences, of course only direct ob- servation can have weight in the decision of such a question. In every case of ontogenetic segmentation the nucleus itself remains passive, and is drawn into the formative activity by non-nuclear plasm. The chromosomes, the only enduring constituents of the nuclear plasm^ are, however, bearers of an indispensable function, though not of for- mative import. As already suggested, it is likely connected with the vital j)rocess of_oxydation, which suggestion is supported by the blood- corpuscles being of nuclear origin. THE PROBLEM OF THE LIVING FORM. The blending of two or more Protozoa into a proportionately enlarged individual without disturbance of the specific structure of the species, is a fact of nature readily observable. This occurrence proves that the specific form of protoplasmic beings is not directly dependent on the amount of substance entering into it. Driesch succeeded in bringing about the union of two segmented eggs of Echinus, and obtained perfect single individuals. Zur Strassen obtained giant embryos of Ascaris formed by the fusion of two eggs. The remarkable results of exjieri- ments attained by grafting point to the fact, that the more or less inti- mate blending or coalescence of the living substance of difl;erent indi- viduals is dependent on specific complemental affinity attaching to the chemical constitution of the substance of the coalescing organisms or fragments of the same. The highly significant fact, that organic form and structure is not directly dependent on the amount of formative material entering into their constitution, is most strikingly revealed in the production of com- plete embrA-onic forms from almost any fragment of egg-plasm, which 80 Vitality and 0 rgamzation of Protoplasm. though proportionately reduced in size^, resemble in all essential struc- tural details the normal embryo. It has been here demonstrated that the organic form in all its struc- tural details is the visible expression of the specific chemical constitution of the living substance composing it. Consequently, in the intricacies of this chemical constitution has to be sought the explanation of the phenomena under consideration. The potency of a chemical fragment to develop into a full-sized embryo, when supplied with sufficient com- plemental material; or, failing this supply, the potency to transform its own substance into a proportionately-sized embrj^o; this potency of fragments to reconstruct the complete typical embryo out of whatever amount of formative material is available, seems to indicate that each definite link in the chemical structure underlying the specific form of an organism is a subordinate formative division, which has power sep- arately to increase in bulk or grow to adult stature in proportion as it is supplied with nutrition or complemental material. And this suppo- sition seems to be corroborated by the mosaic-like morphological divi- sions, which make their appearance during ontogenetic evolution. And corroborated also by the separate regenerative power of such mosaic-like divisions, or structural provinces. In normal ontogeny the blastomeres of each stage of segmentation have to be regarded as the merging into morphological visibility of latent dispositions in the chemical structure of the germ-plasms during its process of gradual reintegration. Each blastomere contains then potentially all structures to be eventually evolved from it. Each suc- cessive segmental division or segregation curtails and distributes thus the potential areas of reproduction, confining them to specific portions of the evolving substance. And when, at last, such formative morpho- logical subdivisons have reached their climax, and have conjointly re- produced the adult organism; then it is found that such morphological areas may still possess more or less separate reproductive potentiality, as evidenced by manifold phenomena of regeneration. And the less highly differentiated such morphological areas have come to be, the more reproductive potentiality do they generally retain. In this light it becomes irrefragably certain that in ''multicellular" organisms the divers ''cells" that compose their specific tissues are as direct derivatives of progi-essive segmentation, not autonomous lineal descendants of an elementary mother-cell; but very obviously definite morphological subdivisions, arising during progressive ontogenetic evo- lution as complemental constituents of a predetermined whole. And as such they may likewise retain reproductive potentiality of their own; may undergo mitotic division, or may even as epithelial "cells" repro- duce highly complex structures. That which is visibly revealed as vital organization in all its minutely differentiated and functionally interdependent structures proves to be the morphological manifestation of what our scientific experience teaches us to regard as specific chemical and specific vital potencies. Vitality and Organization of Protoplasm. 81 The chemical potencies evince themselves as forming unitary bodies, all of whose constituent parts, though consisting of heterogeneous ele- ments known to enter into their composition, are, nevertheless, some- how intimately blended so as to form integrant and not merely aggre- gated components of the same. They evince themselves, furthermore, in displaying specific modes of action and reaction nowise deducible as combined mechanical effects of the spatial arrangement and modes of motion of the component elements. The chemical body acts and reacts as a specfic whole; not simply in one definite mechanically quan- titative manner; but in manifold peculiar and diverse qualitative ways. The specific vital potencies evince themselves, above all, in the power of certain such phyletically elaborate chemical wholes to reintegrate themselves, after partial disintegration, through assimilation of comple- mental material. The integrity, and therewith the identity of the or- ganic being as a whole, is thereby preserved, despite functional and other modes of deterioration. Every part of an organism is a comple- niental fragment of the whole, and not merely an aggregated compo- nent. Germs of all kinds are such fragments, endowed with the power of reintegrating or regenerating the whole of which they are fragments. This reproduction of the whole organism as final aim of the ontogenetic process, resulting, moreover, in its complete adaptation to the medium with which it is to enter into manifold modes of interaction; this strik- ing and undeniably purposeful evolution towards a predetermined end serves as prototype for the conception of teleology in nature^^ or of. so- called final causes. Such strange constructive aiming at the attainment of something whose future existence and constitution are strictly prede- termined, yet only potentially jiresent, has ever been one of the princi- {)al puzzles of philosophy and natural science. It finds its explana- tion solely in biological conditions, and exclusively applies to the same.* *"We are confronted by the nnieh-vexed, yet still open problem, how differ- ent units come to be constitutionally destined to enter into interdependent rela- tions so as aimfully to form an oiganically efficient whole." ''This consideration of innate reciprocal dependence in the constitiition of a larger whole involves the entire teleological riddle; the puzzle, namely, how the integral constitution of a whole, eventuallj to be formed, can possibly act as a so-called final cause, act as the chief determining cause of the nature, disposition and function of the constituent units that enter into its formation. Kant sought to argue away t(deology in nature by declaring it to be a pecu- liar mode of our conception of a certain order of things. He held that every occurrence in nature being strictly dependent on immediate or so-called efficient causation, final causes could not possibly enter into the system of nature. And ,\ recently, much in the way of Empedocles of old, natural selection has been be- ' lieved more particularly to reduce all seeming teleology in nature to mechanical [ or, at least, to elfieient causation. In fact, the principal aim of our present scientific interpretsition of nature is to attribute all its occurrences to adequate mechanical causation. Natural science, when it interprets organization as resulting thus simply from the peculiar rearrangeinent of so many pre-existing material units moved by so much pre-existing energy, misses in its explanation all that is most essen- tial to an adequate understanding of the case. The fact here overlooked, the essential fact, is that in the process of orgajiic development new modes of aim- r-- • 82 Vitality and Organization of Protoplasm. . ful energy, manifest in specific modes of vital reaction of the organism in rela- tion to its medium, come creatively into existence. All that is most character- istic of vital organization and its activity, all that constitutes its specific nature, merges thus newly produced into being, resulting from potencies not previously realized. This amounts not altogether to a creation out of nothing; btit it is N a coming into existence of efficiencies previously non-existent. It is evident, explain it as we may — a living being in relation to its organic and inorganic environment is found to be out and out te.leologically developed. Its organization is preconcertedly constituted for life in a specific medium. And the development of an organism from a reproductive germ is obviously teleologically predetermined by the natvire of the organism to be developed therefrom. The exact plan of the whole being, eventually to be formed as a product of nature, enters here somehow as a final cause in its reproduction." This was written seventeen years ago in an article in \\hich I aimed to prove the radical difference obtaining "between the so-called social organism and the actual vital organism. -International Journal of Ethics," Vol. VIII, pp. 58. 59, 1887. EDMUND MONTGOMEEY. Hempstead, Texas. Eebnmry 23. 1904. AITHORS NAMED. Page E. Alhreclit 51 R. V. Biier. 68 L. Beal 75 C. B rnard 50 M. Bichat 69 C. Bonnet 68 C. Born 55 Th. Boveri 47, 75 C. Darwin 12, 14. 20, 21, 26, 27. 49 Y. Delage 76 R. Descartes . .• 50 H. De Vries 21, 26, 27, 49 H. Driesch....47, 51, 52, 56, 57, 58, 60, 61, 66, 69, 74, 76, 77, 79 R. V. Erlanger 76 C. Fromniann 54 A. Gruber 47 \V. Haaeke 55 E. Haeekel^ 14, 16. 17, 26, 27, 47, 49 A. V. Haller 68 A. Herlitzka 47 0. Hertwio- 20, 56, 69 R. Hertwig 76 R. and O. Hertwig 47, 76 E. Kant 81 J. Liebig 50 F. Lillie 47 1. Loeb 62, 69 H. Lotze .' 50 E. Mach 51 J. R. Mayer 40 F. M. Morgan .38, 47, 56, 64, 69, 74, 76 Job Mueller 50 Page V. V. Xaigeli 16-19. 26, 27, 49 M. Nu.ssbauni 47 L. Oken 58 G. Pfeffer 54 E. Pflueger 48, 55 R. Reaumur 46 Job Roinko 40, 49 L. Rbumbler 36 W. Roux 55, 56, 68, 74 Fnsc- Scbelling 58 M. Schultze 30 E. Scb'ulz 56 H. Sedgwick 56 H. Spencer 70, 72, 26, 27 E. Strasburger 20, 54 E. Tciehmaiin 76 Townsend 74 Trembley 46 8. Watase 69 S. Vines 54 R. Vircbow 50 A. Weismann....20, 25, 26, 27, 49, 66, - 74, 75 W. M. Wbeeler 79 C. O. WTiitman 57 E. B. Wilson 47, 77 Wilson E. Matbews 75, 76 G. Wolff ..46, 65 Bf. Wolff :... 68 H. E. Ziegler 70 L. Zoya 47 O. Zur Strassen 79 .-^^