570 • VERA DANCHAKOFF 



significance, and that the development of the ovum can take 

 place without participation of the spermatozoon. The fertili- 

 zation, or rather the calling forth of development, must neces- 

 sarily consist in activation of chromatin synthesis at the expense 

 of the cytoplasm. These processes may be related to morpho- 

 logically appreciable scattering of the basophilic accumulations, 

 and, as shall be seen later, to a flowing of the chromatic substance 

 to the achromatic frame-work of the nucleus. 



The natural stimulation of the egg to development is a complex 

 process. The presence of the spermatozoon within the ovocyte 

 not only incites the latter to development, but also induces 

 complex chemical changes, which as their consequence have a 

 partial transmission of the paternal hereditary qualities and 

 perhaps also the development of new qualities. And yet, dif- 

 ferent as the normal and artificial stimuli may appear, they both 

 incite similar, changes in the ovum. These changes concern a 

 very exact morphological process — a diffuse scattering of the 

 basophilic substance in the cytoplasm. Whether this diffusion 

 results only in the flowing of the basophilic substance to the 

 nucleus, or whether this process may have a connection with the 

 synthesis of the chromatic substance is difficult to determine. 



A closer study of the preparations gives no indications of a 

 fragmentation of the larger masses, as such. The large baso- 

 philic accumulations appear invariably immediately after normal 

 fertilization and in the beginning of parthenogenetic develop- 

 ment, surrounded by a more diffuse zone of intensely staining 

 cytoplasm. It seems that the chromatic masses formerly clearly 

 defined now undergo a gradual dissolution, and thereby impreg- 

 nate the surrounding cytoplasm. The cytoplasm around the 

 chromatic accumulations exhibits a pronounced reticular struc- 

 ture, some of the meshes of the reticulum being arranged radially 

 to the chromatic accumulations. The diffusion of the chromatic 

 accumulations in normal fertilization is accomplished slowly, 

 but effectively and finally leads to quicker development than 

 during parthenogenesis. The chromatic substance, which, now 

 more diffusely impregnates the cytoplasm, does not remain in 

 fertilized eggs in loco, but in its new physical state is readily 



