420 BOWEN. 



PLATE I. 



Figures 1 and 2 are from Arvelius albopundatus; Figures 3, 4, 7 and 8 are 

 from Euschistus euschistoides; Figures 5 and 6 are from Rhyiidolomia senilis; 

 Figures 9 and 10 are from Chlorochroa uhleri (= persimilis). The large and 

 small cells in each pair are from the same testis in every case. Figures 2, 4, 6, 



8 and 10 are from cells of the large generations; the others are from cells of one 

 of the smaller generations. 



1 and 2 Primary spermatocytes in late growth period. (Flemming-hema- 



toxylin.) 

 3 and 4 Spermatids, stained to show the nebenkern. (Flemming without 



acetic plus cone, nitric acid-hematoxylin.) 

 5 and 6 Spermatids, stained to show the chromatoid body. (Flemming- 



hematoxylin.) 

 7 and 8 Spermatids, impregnated to show the Golgi apparatus. (Modified 



Kopsch.) 



9 and 10 Spermatids, stained to show the acrosome just after the casting off of 



the acroblast. (Flemming-hematoxyUn.) 



