STUDIES ON INSECT SPEKMATOGENESIS. _ 415 



The points brought out in this study may be briefly summarized : — 



1. Di- or poly-megalous sperms are not confined to the genus 

 EuscMstus, as JMontgomery beUeved, but are of frequent occurrence 

 throughout the Family Pentatomidae. 



2. As a result, generations of at least two or three (possibly more) 

 sizes of sperms are developed. 



3. The differences in cell-size are due to increase of all the con- 

 stituents of the cell except the chromatin, which is constant in amount, 

 at least within veri/ narrow limits. 



4. The large sperms are differentiated by a process superficially 

 unlike, but fundamentally similar to, that which the small sperms 

 undergo. 



