66 CYTOLOGY chap, n 



a temporary lengthening out of the chromosomes in the diplotene stage 

 {e.g., Tomopteris, Fig. 14, H, I), which may perhaps be considered an 

 indication of a tendency to pass into a germinal vesicle condition. The 

 " confused stage " of certain insects (Fig. 17) represents a sHghtly more 

 marked, but still rudimentary, condition of the same stage. In some 

 Ostracoda (Fig. 28) there is a stage in spermatogenesis closely corre- 

 sponding to the germinal vesicle of the oocyte, the resemblance even 

 extending to the formation of " yolk nuclei " in the cytoplasm (Schmalz, 

 1912). In the Myriopod Scolopendra (Blackman, 1905) where the 

 primary spermatocyte undergoes an unusually pronounced growth, the 

 resemblance to the oocyte germinal vesicle is even greater (Fig. 28). 



