300 BULLETIN OF THE 



Such, according to this author, is the nature of the process for only 

 a limited number of segmentations, however. Toward the end of yolk 

 cleavage — when the segmentation begins to be no longer easily dis- 

 cerned by the unaided eye — the cluster of nuclear germs (Kernkeim- 

 haufen) melts together into a solid corpuscle, which retains for some 

 time an irregular outline and a netlike pattern, — the last trace of its 

 composition out of separate nuclear germs, but which eventually becomes 

 a sharply defined, round, finely granular " cell nucleus." The division 

 of the cell nucleus results from a one-sided outgrowth, not from an elon- 

 gation, as in earlier segmentations. 



It is impossible to review here in detail the extended reasoning put 

 forward by Goette to show that neither the unfertilized nor the fecun- 

 dated egg are living substance, and how that, during the yolk division, 

 both the whole yolk sphere and the individual yolk masses [segmenta- 

 tion spheres] are lifeless stages of transition from unorganized matter to 

 an actual [living] organism (p. 77). 



Having discovered that the physico-morphological conception of the 

 cell is incompetent to stand for a complete definition, he seems to fall 

 into an equally exclusive method of reflection, and denies that the egg 

 is a cell because it fails to exhibit to him one of the functional peculiar- 

 ities of living things. It does not live because he discovers no process 

 of nutrition (Ernahrung), and that there is no such thing as a nutritive 

 function is confirmed, sufficiently for him, by the single fact that the 

 egg does not grow, — does not increase in size, except in a manner quite 

 foreign to the method of growth in living cells. Thus denying the ad- 

 equacy of the morphological conception, he will not even allow any other 

 functional manifestation than that of growth to stand in evidence for the 

 living condition of the egg, or its real cell nature. The motive to such 

 a theory of the transition of lifeless to living matter has, to say the 

 least, not been strengthened by the accumulating evidence of a genetic 

 connection between the germinative vesicle and the subsequent genera- 

 tions of nuclei. 



According to Goette, the formation of the " life-germ " and its area 

 is only the result of a radial diffusion (p. 88), the optical expression of 

 which has already been noted, and the life-germ, in its turn, causes in a 

 certain way the continuation of this diffusion. The only essential dif- 

 ference between the developing and the not-developing egg lies in the 

 regulation in one case, and the want of regulation in the other case, of 

 the osmotic process which takes place in both instances between the 

 yolk and the water surrounding it. 



