The Science and Philosophy of the Organism

water form of amphibious plants, or the differences between the same species of plants in the Alps and in the plains, or

nd of it; at least it never occurs previous to the full individual life of an organism, pre

THE CONCEPT

while to the study of plants. There exist very many external formative stimuli in the morphogenesis of vegetation: would it then be possible to regard every effect of such an external formative stimulus as a real morphological adaptation? No; for that would not meet the point. The general harmony of form is indeed concerned if gravity forces roots to shoot forth below at a spot where they can enter the ground, or if light induces branches and

on some specific means, though it does not owe its localisation to that means as its "cause"? It seems to me that such a view would also fall wide of the mark. It is well known, for instance, that the flowers of many plants never fully develop in the dark; light is necessary for their morphogenesis. Is, therefore, their growth in the presence of light to be called a morphological "adaptation" to light? Certainly not: they simply cannot originate without light, because they require it for some reason. It is precisely here that our conception of light as a "means" of morphogenesis is most fully justified. Ther

in itself an example of adaptation, nor are processes dependent for their existence on any kind of condition or means to be cal

; but as functioning itself, at least in plants, certainly stands in close relations to the medium, it follows that all adaptations are in the last resort connected with

ept, in the realm of causal concepts in general, by clearly stating the point that adaptations are related directly to functionality, and only indirectly, through functionality, to external changes. By the aid of this logical formulation we now are entitled to apply the term "cause," in our restricted sense of the word, to every change of the medium which is followed by any sort of adaptation in regard to itself

phogenesis proper as an accomplished fact. Morphogenesis proper has laid the general lines of organisation; and now adaptation during the functional life, so to speak, im

wo groups, one of them embracing adaptations with regard to functional changes from without, the other adaptations to those functional changes which come fro

UNCTIONAL CHANGE

ntial factor to which "adaptation" occurs in amphibious plants, though the changes of the mechanical conditions according to the medium also seem to have some sort of structural effect. If plants stand very deeply in water, the conditions of illumination, so important for assimilation in plants, may have been altered, and therefore much of the structural change can be attributed also to them. It is unimportant in our general question what i

case of the more complicated modification, but nothing else. Indeed, all morphological adaptation has been conceived as only consisting in differences dependent upon the absence or the presence of necessary means or causes of development, and as offering no problem of its own. We have gained the ri

erely a necessary "means": then why is the histological consequence of the presence of the means an actual adaptation to it as far as its relation to functioning is concerned-why is the consequence of

absolutely overlooked by those who have been pleased to deny

ations" for cases such as those described, for instance, by V?chting,79 where not merely one and the same tissue originates adaptively with regard to the degree of its normal functioning, but where a profound disturbance of all functioning connections, due to the removal of portions of the organisation, is follow

g structures in their terrestrial forms, and therefore have wrongly been regarded as simply due to a stopping of morphogenesis for want of necessary means, yet there are a few of them that are positive complications in comparison with the land-forms: the so-called a?ren

The larvae, however, may be removed from the mother's body at an earlier stage and forced to complete their development in water. Under these circumstances, as was shown in an excellent memoir by Kammerer,80 they will change the whole histological type of their gills and skin in order to meet the n

TIONAL AD

econd group of these phenomena, which in our analytical discussion we have called adaptations to functional changes that

ll known that the muscles get stronger and stronger the more they are used, and that the same holds for glands, for connective tissue, etc. But in these cases only quantitative changes come into account. We meet with functional adaptations of a much more complicated and important kind,

of vertebrates. All these structures, indeed, are such as an engineer would have made them who knew the sort of mechanical conditions they would be called upon to encounter. Of course all these sorts of mechanically adapted structures are far from being "mechanically explained," as the verbal expression might perhaps be taken to indicate, and as indeed has sometimes been the opinion of uncritical autho

ed to exist; they also occur in a very high perfection in the connective tissue, in the muscles and in the bone tissue of vertebrates. Here indeed it has proved possible to change the specific structure of the tissue by changing the mechanical conditions which were to be withst

ich result from the very nature of functioning. In fact, the actual state of all functioning tissue, the intensity of its state of existence, if you care to

he word "medium" being taken as embracing everything that is external to the reacting cells. But of course also here the demonstration of single formative agents does not detract in the least from the adaptive character of the reaction itself. So we may say, perhaps, that localised pressure is the formative stimulus for the se

ICAL CO

en may go hand in hand, as is most strikingly shown in a fine series of experiments carried out by V?chting, which we have already alluded to. Here again I should like to lay the greatest stress upon the fact that, in spite of such actual connections, restitutions and adaptations always have been separated from another theoretically, and that the forms are never to be

structures, such as those of bones, we have seen to originate in ontogeny previous to all specific functions, though for the help of them, to say nothing of the processes of the mere outlining of organisation during cleavage and gastrulation. But they are "inherited" adaptati

ining new material for our further philosophical analysis, we have reluctantly to confess that, at present at least, it does not see

th regard to adaptation, and so perhaps it may seem as if the concept of an "answering reaction" ("Antwortsreaktion"), which was introduced into science by Goltz87 and which is to play a great part in our discussions of next summer, may come into account: bu

s of its disturbed or changed functional state. We are speaking of facts here, of very strange ones indeed. But I feel unable to formulate a real proof against all sorts of mechanism out of these facts: there might be a machine, to which all is due in a p

te of functioning, in a way which normalises this state histologically. And it is a fact also that even cells, which are not yet functioning but are in the so-called embryonic or indifferent condition

ls or to change their histological qualities fundamentally; in technical terms, they can only assist "hypertrophy" but not "hyperplasia." Any adaptive change of a tissue therefore, that implies an increase in the number of cellular elements or a real process of histogenesis, has to start from "indifferent" cells, that is to say, cells that are not