72 



bulletin: museum of comparative zoology, 



continuous at the central pole and that at no time is there a distinct 

 vesicle for each chromosome. It is impossible to distinguish the mon- 

 osome with certainty during this stage as Sutton (:00, :02) has been 

 able to do in Brachystola, but in some cases one of the chromosomes 

 has a somewhat different appearance and is surrounded by a more 

 distinct vesicle. Judging from Sutton's work, this is probably the 



B. 



6'- 



V-f;»5 



Figs. B.-E. — Polar views, metaphase of spermatogonia showing autosome 

 pairs. X 1450. 



Figs. B and C. — Dissosteira Carolina. 

 Fig. D. — Arphia tenebrosa. 

 Fig E. — Chortophaga viridifasciata. 



monosome, but in this species the difference from the other chromo- 

 somes is not great enough to render it distinguishable in most cases. 

 However, even at the height of the resting stage there can sometimes 

 be recognized a more or less distinct vesicle in which the chromatin is 

 more densely aggregated than elsewhere. This vesicle with its more 

 deeply staining chromatin usually extends out into the cytoplasm near 



