SMITHSONIAN MISCELLANEOUS COLLECTIONS 



VOL. 89 



Singh Pruthi says, the median oviduct (" uterus ") begins as an in- 

 vagination at the posterior margin of the eighth sternum, and a 

 " spermathecal " invagination is formed on the ninth sternum. " Grad- 

 ually the walls intervening between the two organs (the mid-ventral 

 region of the spermatheca and the mid-dorsal of the uterus) disappear 

 so that their cavities freely communicate with each other." Thus 

 the " uterus ", Singh Pruthi says, comes to open " into the sperma- 

 thecal rudiment and communicates with the exterior through the open- 

 ing of the latter, behind the ninth sternite ". The development of the 

 anterior section of the oviduct from the seventh segment is evidently 

 not recapitulated in Tenebrio. 



The clear account of the development of the exit apparatus of the 

 female genital system in Coleoptera as given by Metcalfe (1932) 



Fig. 5. — ^Diagranis showing the development of the female exit apparatus in 

 Coleoptera (from Metcalfe, 1932). 



A, prepupal stage of Sitodrepa with anterior invagination (a) behind eighth 

 sternum, and posterior invagination (b) behind ninth sternum. 



B, union of the two invaginations to form the definitive copulatory pouch and 

 egg passage (a -f b), with spermatheca (Spt) opening into diverticulum (d) of 

 its anterior end. 



is in essential agreement with that of Singh Pruthi. In Sitodrepa, 

 Gastroidcs, Anthonornns, and Rhagium, Metcalfe finds that there 

 are formed in the prepupal period two tubular genital invaginations 

 of the body wall (fig. 5 A, a. h), one opening between the eighth 

 and ninth abdominal sterna, the other behind the ninth sternum, the 

 second lying immediately dorsal to the first. The anterior, ventral 

 ttibe (a) bifurcates at its anterior end, and the mesodermal oviducts 

 eventually unite with its two arms. The posterior, dorsal tube (&) 

 gives off diverticula anteriorly which develop into the sperm receptacle 

 and " accessory " glands of the adult beetle. Finally, during the early 

 part of pupation, the two tubes tmite with each other for most of 

 their length (B), the intervening walls disappear, and the opening 

 of the anterior tube on the eighth venter is closed. The definitive 



