In the female reproductive system ova are produced in an ovary and from 

 thence pass down an oviduct into an albumen gland where they are surrounded by 

 an albuminous secretion. Since the egg? are enclosed within a common mass of 

 albumen, embryonic cannibalism is made possible during subsequent stages of 

 development. Fertilization of the ova probably occurs in the albumen gland. Next 

 the mass of eggs suspended in albumen is moved by muscular and ciliary activity 

 into a large capsule gland which secretes a wall of mixed proteins and mucoid 

 materials about them . At one end of the capsule a plug of mucus is moulded into 

 position by a special part of the gland. The capsule gland connects with the outside 

 by way of a short tube which terminates in the vaginal opening. During copulation 

 seminal fluid is received within the vagina and from thence at a later time sperm 

 move across the capsule gland to a seminal receptacle where they are stored 



The vagina opens to the exterior on the right anterior side ox the mantle 

 cavity, ventral to the anus. The egg capsule, roughly formed by the capsule gland, 

 is forced out of the vagina and is carried along a temporary groove on the right 

 side of the foot to the pedal egg capsule pouch in the sole of the foot . Within this 

 it is moulded into its final shape, its walls are hardened, and adhesion to the sub- 

 stratum is effected 



Although Fretter reports that copulation is of frequent occurrence in 

 .both English drills, it has never been recorded for U. cmerea . A single labor- 

 atory observation in Eupleura caudata, close relative of Urosalpinx, has been 

 described by Stauber (1943) and is worth repeating because of its possible similar- 

 ity to that in Urosalpinx. Preparatory to copulation a small male Eupleura mounted 

 a large female and assumed a position on the right anterior side of the shell . During 

 copulation the front mid longitudinal third of the male's foot was depressed into a 

 groove and the penis was extended over this and around the rim of the shell of the 

 female into the vaginal opening, After numerous interruptions the male was repeat- 

 edly successful in relocating the female and persisted in copulation . Under the 

 conditions of these observations copulation continued intermittently for 21 days. 

 A study of the gonads and behavior of representative stages in the life cycle of 

 Urosalpinx isolated in the egg case stage should contribute materially to our knowledge 

 of reproduction in this drill , 



At first Cole (1941) considered that sex reversal might occur in_U. cinerea, 

 but further work by him (1942) demonstrated to his satisfaction that there is no 

 evidence to support this hypothesis. Twenty drills caught in. the act of spawning were 

 isolated for the summer and showed no sexual change by fall. In addition a careful 

 search among thousands of drills disclosed no individuals with characters inter- 

 mediate between those of male and female. In confirmation of these studies drills 

 should be isolated over a longer period of time and histological studies of the gonads 

 of sample drills should be made periodically 



28 



