STUDIES ON INSECT SPERMATOGENESIS. 



395 



earlier statement that a smaller generation occurred in lobe 1, an 

 inaccuracy due, perhaps, to a typographical error. His later descrip- 

 tion is certainly correct for Euschistus variolarius and E. euschistoides 

 and probably for all the other species of the genus as well. Mont- 

 gomery now considered the dimegaly as " due directly to differences of 

 the nurse cells of the different follicles, i.e., to degree of nutrition." 



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Figure 2. Outline drawings showing extent of nucleus and cytoplasm in 

 primary spermatocytes of the late growth period (xl450). (Flemming- 

 hematoxylin.) Row I, Murgantia histrionica; Row II, Euschistus variolarius; 

 Row III, Artelius niboptmciatus. Columns A, B, C, — cells of the smallest, 

 small or normal, and large generations respectively. 



He also added definite proof of size differences in the heads of the 

 sperms, showing from sections that each of the three spermatocyte 

 generations gave rise to sperm the heads of which were likewise of 

 three sizes. That these general size differences are constant and not 



