PLATES 16 AND 17 



EXPLANATION OF FIGURES 



136 to 147 Acridium granulatus Scudd. 



136 to 140 From walls of ovariole of ovary of one animal. Fourteen chromo- 

 somes present. Five long ones instead of four. One long chromosome (1) 

 is probably a mate to the normal no. 1. 



141 to 147 First spermatocyte divisions from one male. Note that all chromo- 

 some pairs are present and normal, except the smallest (no. 1), which is made up 

 of a normal no. 1 and an abnormally long mate (1), from which it is separat- 

 ing. The abnormal chromosome is constricted at a point as far from its distal 

 end as the length of its no. 1 mate (figs. 142, 144, 146, 147). 



310 



