EXPERIMENTAL MORPHOGENESIS 61 



blastula was swimming about. I was so much convinced 

 that I should get Koux's inorphogenetical result in all its 

 features that, even in spite of this whole blastula, I now 

 expected that the next morning would reveal to me the 

 half-organisation of my subject once more ; the intestine, I 

 supposed, might come out quite on one side of it, as a half- 

 tube, and the mesenchyme ring might be a half one also. 



But things turned out as they were bound to do and 

 not as I had expected ; there was a typically whole gastrula 

 on my dish the next morning, differing only by its small 

 size from a normal one ; and this small but whole gastrula 

 was followed by a whole and typical small pluteus-larva 

 (Fig. 5). 



That was just the opposite of Eoux's result : one of the 

 first two blastomeres had undergone a half-cleavage as in 

 his case, but then it had become a whole organism by a 

 simple process of rearrangement of its material, without 

 anything that resembled regeneration, in the sense of a 

 completion by budding from a wound. 



If one blastomere of the two- cell stage was thus capable 

 of performing the morphogenetical process in its totality, 

 it became, of course, impossible to allow that nuclear 

 division had separated any sort of " germ-plasm " into two 

 different halves, and not even the protoplasm of the egg 

 could be said to have been divided by the first cleavage 

 furrow into unequal parts, as the postulate of the strict 

 theory of so-called " evolutio " had been. This was a very 

 important result, sufficient alone to overthrow at once the 

 theory of ontogenetical " evolutio," the " Mosaiktheorie " as 

 it had been called not by Eoux himself, but according to 

 his views in its exclusiveness. 



