STUDIES ON GERM CELLS 



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its larger sister cell as the first 'Urentodermzelle' (fig. 22, C, E). 

 The primordial germ cell is the last to divide during the sixth 

 cleavage and the 'besondere Korper' does not, as before, pass 

 entire into one of the daughter cells, but breaks up into a number 

 of pieces, part of which are included in each of the two daughter 

 cells (fig. 22, D, E, X). One of these daughter cells apparently 



Fig. 22 Sagitta (redrawn from Elpatiewsky, '09, '10). A, first appearance 

 of the 'besondere Korper' {hK) in the egg. B, egg with germ nuclei fusing. A', 

 'besondere Korper.' C, thirty-two cell stage; the primordial germ cell (G) con- 

 tains the 'besondere Korper' (A). D, division of 'besondere Korper' (A) during 

 division of primordial germ cell. E, two primordial germ cells showing unequal 

 distribution of 'besondere Korper' (A'^). F, division of first two primordial germ 

 cells; one dividing more rapidly than the other. 



acquires more of the 'besondere Korper' than the other. This 

 division appears to Elpatiewsky to be differential, separating 

 the primordial oogonium from the primordial spermatogonium, 

 the latter being the cell which receives the larger portion of the 

 'besondere Korper' and which during the next (seventh) division 

 is shghtly delayed (fig. 22, F). Subsequent to the seventh 

 cleavage the remains of the 'besondere Korper' become pale and 



