STUDIES IN SPERMATOGENESIS 



PART n. 

 (Pages 33-7^. 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 



's;.r;i!;:iH;;!:;s;GTON, D. C. : 



Published by the Carnegie Institution of Washington 



October, 1906 



