258 VERA KOEHRING. 



there is no apparent symmetry in the bilateral arrangement of 

 the tubules, the necks from each side converge separately which 

 causes two reservoirs and these, joining, form the large chamber 

 of the central tubule. This narrows abruptly into the long, 

 narrow dorsal passage which dips into the cloaca. 



In this largest spermatheca as in some others which are 

 presumed to be several breeding seasons of age, the central tubule 

 extends quite to the posterior wall of the organ and, coincident, 

 are the exaggerated curves of the necks of the flask tubules. 

 All of the tubules lie in the floor of the organ but the most anterior 

 have their blind end walls faced anteriorly. The necks then 

 curve posteriorly and dorsally. The epithelium in this oldest 

 series is particularly conspicuous and the whole thing is an 

 organ of striking beauty, in size approximately 2/3 mm. long. 



III. 



RELATION TO CLOACA. 



The development of the cloaca from the simple smooth-walled 

 stage of larvae to the complications of sexual maturity cannot 

 well come within the scope of this paper, but a brief summary 

 and a short description of the mature conditions should not be 

 out of place in explaining some of the relations of the spermatheca. 



The most distinctive feature of the cloaca after metamorphosis, 

 aside from the development of the mucous glands, is the formation 

 of a short, dorsal papilla midway between the vent and the 

 opening of the oviducts. This lengthens antero-posteriorly 

 becoming a fold and also deepens until it appears in sections like 

 an icicle pendent from the roof of the cloaca. Until a period 

 shortly preceding sexual maturity the walls of this fold are 

 comparatively smooth. Then they become folded and especially 

 modified at the tip. The tip broadens into a flat surface with 

 two wings which extend close to the lateral walls of the cloaca 

 so as to form two virtually closed dorsal passages through the 

 cloaca up to the opening of the spermatheca where the entire 

 fold ends. The fold undoubtedly functions as an egg guide 

 causing a kind of continuation of the oviducts into the cloaca, 

 but the function of the two small blind pouches in the posterior 

 region of the fold is unknown. 



