724 THE GENERATIVE ORGANS. 



menon in 1871, with some observations communicated to me 

 by the late distinguished Coleopterist, Dr. J. A. Power. 



The early maturation of the sperm may be termed Protandry , 

 and compared to the analogous condition in hermaphrodite 

 plants. Protandry is widely spread amongst hermaphrodite in- 

 vertebrates, and the early transference of the sperm to the female 

 organism in Insects is perhaps an indication of an hermaphro- 

 dite ancestral condition. The protandrous condition of Insects 

 does not appear to have attracted the attention which this re- 

 markable phenomenon deserves. 



If one may venture to generalise, it appears to me probable 

 that the existence of spermathecse in the developed female is 

 connected with this protandrous condition. In the Lepidop- 

 tera, in which it does not exist. I have sought in vain for sper- 

 mathecas ; their place is probably taken by the large bursa, 

 which is connected with the oviduct by the spermatic canal, 

 and, so far as I can judge, those who have described sper- 

 mathecae in these Insects have mistaken other structures for 

 them. They certainly exhibit nothing like the spermathecse of 

 the Diptera and Hymenoptera. 



The single so-called spermatheca of the Cockroach Peri- 

 planeta orientalis is evidently a bursa similar to the bursa of 

 the Lepidoptera. 



In the Diptera, as has been already stated, there is no bursa 

 properly so called, and it appears probable that this organ is 

 represented by the uterus, in which the ova in some genera are 

 normally retained until the embryo is fully developed, or even 

 until the larva is ready to pass into the pupa stage. 



5. THE EXTERNAL GENERATIVE ORGANS. 



a. General Considerations and Nomenclature of the Abdominal 



Segments. 



Although in some Insects the external generative organs are 

 exceedingly simple, in others their complexity is very great ; yet 

 no definite nomenclature has been established by which the 



