210 An?ials Entomological Society of America [Vol. XV, 



appears to be the ninth, a small anal segment, one pair of 

 articulate genital styles and a median aedeagus. They are so 

 similar that it appears only logical to conclude that they have 

 a similar origin and development. At least it urges us to 

 study the pupal stage and the immature imago to see if any 

 evidence of such a development can be found. The Lepidoptera 

 possess no cerci in the males while the Trichoptera possess 

 cerci. 



Elsewhere one of the authors has insisted that no evidence 

 has been brought forward to show the homology between the 

 male and female genitalia of Coleoptera, and that in many 

 forms the male gonopore appears to open between the ninth 

 and tenth sternites. If in the Homoptera the coxites can be 

 disassociated from the eighth sternite and become amalgamated 

 with the ninth tergite so as to appear as the ninth sternite, 

 it is highly probable that the same has happened in Coleoptera. 

 But until direct evidence is brought forward showing that 

 such is the case, we must not dogmatically assert that it has. 

 Wherever the hypandrium appears as the ninth sternite we 

 must bear in mind the possibility of it being the coxites of the 

 eighth sternite. 



If this homology of the sexes in Coleoptera can be dem- 

 onstrated, it helps us to understand the wonderful coadaptation 

 between the internal sac and the uterus, for they are then 

 true homologies and the cause which, modifies one can modify 

 the other in the same manner. The question is worthy of 

 further study. 



