EPIGENESIS OR EVOLUTION. in 



Wilhelm Roux is no less positive : " Das Ei schon 

 von vornherein aus ensprechend vielen verschiedenen 

 Teilen zusammengesetzt sein muss, dass die Entwicke- 

 lung, also wesentlich Metamorphose von Mannigfaltigkeit, 

 Evolution in unserem Sinne ist, trotz, der formalen 

 Epigenesis C. F. Wolff's ". l Roux, however, seems to 

 be inconsistent in describing the evolutionary product, 

 the cell aggregate, as a "mosaic work," an inconsistency 

 to which I shall have occasion to refer later on. 



Finally, we have the opinion of C. O. Whitman, who 

 in a very able paper 2 calls into question the whole 

 cell doctrine, and gives his adherence to the evolutionary 

 theory in the most unmistakable manner. He says 

 " that organisation precedes cell formation and regulates 

 it, rather than the reverse, is a conclusion that forces 

 itself upon us from many sides ". 



I am not going to accuse any of these authors, who 

 are far too acute to fall into such an error, of confusing 

 the issue between epigenesis and evolution to the extent 

 which might appear from these quotations. Epigenesis, 

 as Roux states, is a formal statement of the observed 

 facts of ontogeny. It has been pressed into the service 

 of speculation, and attempts have been made, we shall 

 see shortly that they still are being made, to form an 

 epigenetic theory to explain the causes of heredity. It 

 is likely enough that these attempts have been hitherto 

 failures ; but the fact that the imaginary and theoretical 

 superstructure has proved to be flimsy does not in the 

 least affect the solidity of the building, on which the 

 superstructure was, in truth, a mere excrescence. There 

 is some reason to fear that, unless a protest is raised, the 

 failure of the attempts to form hypotheses explaining 

 the causes of developmental phenomena on epigenetic 

 grounds, will discredit the doctrine of epigenesis as a 

 statement of the observed facts of development. Weis- 



1 W. Roux, loc. cit., p. 284. 



2 C. O. Whitman, "The Inadequacy of the Cell Theory," Journal of 

 Morphology, vol. viii., August, 1893. 



