254 VERA KOEHRING. 



in one side of the spermatheca, pass longitudinally through a 

 flask and its neck. The spermatozoa are streaming in a mass 

 from the flask into the neck. But other sections show that they 

 have not proceeded as far as the central duct. 



Flask tubules containing spermatozoa show a modification of 

 the epithelium. The tall columnar cells are unrecognizable. 

 There is instead a narrow row of flat cells utterly different in 

 appearance from columnar cells. The delicate part of the cells 

 has completely disappeared and no ragged nor shrivelled edges 

 even indicate its former presence. The width of these cells is 

 i/ioo mm. in comparison with measurements of 3/100 and 

 4/100 mm. during the non-breeding periods. 



Some of this difference might be accounted for by presuming 

 that the tubules are stretched by the mass of spermatozoa 

 contained within them. However, there does not seem to be 

 any such stretching. Measurements of the diameter of the 

 tubules during the breeding season are normal corresponding to 

 the size of the spermatheca. Also when the flasks are cut 

 squarely through, the whorl of spermatozoa is shown lying in 

 the lumen with no adherence to the walls. There is no evidence 

 of crowding or packing. 



II. 



DEVELOPMENT. 



The above description is of a typical mature spermatheca 

 following at least one season of egg-laying. The organ in some 

 specimens which are larger and presumably older differs in 

 some details and will be discussed at the end of this part on 

 the development. 



The development of the spermatheca is to be considered with 

 reference to the growth of the cloacal region also. There is a 

 great deal of change in the whole region from the time of meta- 

 morphosis to sexual maturity. 



The youngest specimen prepared was a 45 mm. female identi- 

 fied by Mrs. Wilder as a stage in early metamorphosis. There 

 is no indication of any spermathecal tubules though the beginning 

 of some cloacal glands may be apparent. In this paper the 

 term "cloacal glands" is applied to the mucous glands of the 



