On the Mechanical Conception of Nature. 699 



positive basis of this hypothesis is insecure. 

 Cases of sudden transformation of the whole 

 organism with subsequent inheritance are as yet 

 quite unknown. It has been shown that the 

 occasional transformation of the Axolotl must 

 most probably be regarded in a different light. 

 Another case, taken for heterogeneous generation, 

 viz. the budding of twelve-rayed Medusae in the 

 gastric cavity of an eight-rayed species, has 

 lately been shown by Franz Eilhard Schulze* to 

 be a kind of parasitism or commensalism. The 

 buds of the Cunince do not spring, as was sup- 

 posed, from the Geryonia^ but are developed from 

 a Cunina egg. But even if we recall here the 

 cases of alternation of generation and heteroge- 

 nesis, this would not be of any value by way of 

 proof ; it would only be thus indicated how one 

 might picture to oneself a sudden transformation. 

 That in alternation of generation, or generally, in 

 every mode of cyclical reproduction, we have not 

 to deal with the abandonment of one type of 

 organization and the transition to some other, is 

 proved by the continual return to the type of de- 

 parture by the cyclical character of the entire 

 transformation. That two quite heterogeneous 

 types can belong to one cycle of development is, 

 however, capable of a far better and more correct 



1 " Uber die Cuninen-Knospenahren im Magen von Geryo- 

 nien." Reprint from " Mittheil. des naturwiss. Vereines," 

 Graz, 1875. 



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