26 Indications of Continued Formative Influence 



to be somatized accidentally remain isolated, in which 

 case the activation of their potential germinal energies 

 would be permitted, which might have been impossible 

 had they remained united with the other blastomeres or 

 cells. 



The possiblity of such receptive indifference toward 

 somatizing stimuli in nuclei which if they were isolated 

 or in other conditions would on the contrary possess and 

 give practical demonstration of very definite specific 

 qualities, is indicated by those cases in which all the 

 nuclear material of the post generated half embryo is 

 furnished by the half already developed. 



Indeed it often happens that on the side operated upon 

 the nutritive yolk alone is utilized; and into this latter 

 emigrate nuclei formed by normal division of the nuclei 

 of already somatized cells in the developed half of the 

 egg. And these emigrated nuclei then bring about the 

 division of the yolk mass of the part operated upon into 

 small indifferent cells only: "With the formation of a 

 right or left half embryo," Roux observes in a later 

 study, "the formative capacity of the uninjured half of 

 the egg is not yet exhausted. On the contrary certain 

 experimental results permit the conclusion that in many 

 cases there is an emigration from it of nuclei, and 

 perhaps indeed, of a little protoplasm also, going out 

 from those points which by the accident of position have 

 the most intimate contact with the side operated upon, 

 toward the contiguous half of the egg deprived of its 

 own capacity of development. These nuclei become 

 distributed throughout the whole of the large mass of 

 yolk and thereupon follows later a breaking up of the 

 half operated upon into cells, and this is not as in normal 

 division a division of the whole mass first into two nearly 



