88 H. B. GOODRICH 



Ascaris megalocephala during the second cleavage (Boveri 

 '99). Thus figure F, the first cleavage and figures G and H, 

 the second cleavage show no diminution whereas in Ascaris 

 megalocephala diminution usually occurs in the cleavage cor- 

 responding to that shown in figure G of the AB cell. There- 

 after as far as followed diminution occurs as in Ascaris lumbri- 

 coides — that is in cells A and B as they form cells a and b 

 (fig. I, and in cell EMSt as it forms E and MSt (fig. K), but not 

 in the keimbahn cells, P as it forms EMSt and P2 (fig. H), P2 as 

 it forms P3 and C (fig. J). Figure 46 from sectioned material 

 shows the nature of the process. A relatively large mass of 

 chromatin is thrown out at the periphery of the metaphase 

 plate remaining as an irregular ring about the central core of 

 spindle fibers as the anaphase plates recede from one another. 

 Figure 47 shows a division without diminution. 



The P cell and its descendents may be distinguished from other 

 cells by possession of yolk spherules present, apparently in 

 greater quantity than in the corresponding cells in Ascaris megalo- 

 cephala. 



