A. RICHARDS. 



Figs. 13 to 17 illustrate the process, but no attempt is made to 

 give even a meagre outline of the behavior of the chromosomes 

 in this period. However, attention is called to the appearance of 

 the spindle. While spindle formation is quite regular, the achro- 

 matic fibres do not stain well and frequently the entire structure 

 is overlooked. This fact taken with the smallness of the chromo- 

 somes and the prominence of the large cytoplasmic granules may 

 well serve to veil the process of mitosis. In many cases one 

 does not, at first, distinguish between the chromosomes and the 



FIG. II. Oogonium ; polar view of an anaphase. This figure and the next are 

 from early generations of oogonia. 



FIG. 12. Oogonium; polar view of a telophase. 



cytoplasmic granules, so nearly alike may they appear. While 

 Fig. i 5 shows clearly its mitotic character, the cell from which 

 it was drawn was overlooked for a long time. 



Fig. 17 is a case which suggests an "endogenous" division. 

 According to Child, an endogenous division is that of a nucleus 

 into two nuclei within the old nuclear membrane. Upon a 

 superficial inspection the cell in question seemed to be in process 

 of such division as shown by the outline in Fig. 18. Careful 

 study, however, revealed the mitotic nature of the division. It is 

 a late telophase with the chromosomes disintegrating ; remnants 

 of asters may be seen, as can a Zwischenkorper. 



The appearance of this cell suggests the question of the rela- 

 tion between nuclear and cell division. Botanists have recognized 

 the distinction between the two processes much more generally 

 than have zoologists. The latter have been-accustomed to regard 

 nuclear division as a sign of immediate cell division. Very often 

 this is not the true state of affairs, for nuclear division may never 

 be followed by cell division (Marshall), or a considerable period 

 of time may elapse before a cell plate is formed. Fig. 1 7 shows 



