Problems of biology / [George Sandeman].

  • Sandeman, George
Date:
1896
Catalogue details

Licence: Public Domain Mark

Credit: Problems of biology / [George Sandeman]. Source: Wellcome Collection.

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    the qualities of the germ and of every succeeding stage. The second view is the “epigenetic” theory of the development of the individual. It is best defined nega- tively, with regard to the features of the first theory. It has no “ vehicle of qualities ” and knows nothing of a (luasi-psychical principle. In a word, it is the critical point of view, and has no hyi^othesis. It may perhaps be dis- tinguished from the other as the evolutionary theory, in so far as “ evolution ” implies the rise of what is complex and heterogeneous from what is comparatively homogeneous and simple, rather than the rise of a less complex system of differences from a more complex system of determinant “ vehicles.” By possibility the epigenetic theory does not signify, as the other does, abstract actuality in another form. The adult qualities are in the germ in possibility but not “ in material representatives ” or in a quasi-psychical know- ledge, for everything that is in the germ is a quality of the germ itself. The epigenetic theory is thus the denial of the second postulate of the systematic biology. Now, the biologists of hypothesis, as they subscribe to the first postulate, also with one accord subscribe, in one form or another, to the second. And some of them say, as they all imply, that the non-epigenetic view of the development of the individual is necessary to the doctrine of adaptation by the transformation of species. In this we shall find that they are right. The three postulates are closely inter- dependent. And because an hypothesis as to the nature of the determination of the form of the individual accompanies, as its complement, every hypothesis as to the manner of the transformation of species, it is necessary to pay that attention to these hypotheses of the germ-representation of qualities, which their frequency, elaboration and confessed importance demand. Now, we have theories in this kind from many authors, but especially from Darwin and de Vries, Spencer, Haeckel
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