STUDIES IN SPERMATOGENESIS 



PART II. 



(PAGES 33-74. PLATES VIII-XV.) 



A COMPARATIVE STUDY OF THE HETEROCHROMO- 



SOMES IN CERTAIN SPECIES OF COLEOPTERA, 



HEMIPTERA AND LEPIDOPTERA, WITH 



ESPECIAL REFERENCE TO 



SEX DETERMINATION. 



BY N. M. STEVENS 







WASHINGTON, D. C. : 



Published by the Carnegie Institution of Washington 

 October, 1906 



