1908] Female Reproductive Organs of Cimbex 93 



or less ovoid nucleus varies in shape and may often be found 

 between the vesicle and the outer boundary of the cell (Fig. 10) 

 or nearer the central part of the cell. In the accessory glands 

 the cell boundaries are very distinct (Fig. 9) but in the ducts 

 these are indiscernable (Fig. 10). The cells of the glands are 

 somewhat larger than those of the duct; the former surround a 

 rather small central lumen, while the lumen of the duct is much 

 larger. 



The nuclei of the "endothelial or centrotubular cells," which 

 are usually crowded up against the chitinous intima or wedged 

 in between the inner ends of the two glandular cells in the acces- 

 sory glands, are found midway in the epithelial layer in the ducts 

 (Fig. 10, en). They can be distinguished easily from the nuclei 

 of the epithelial cells by their smaller size. 



All of these facts would tend to show that the cells of the right 

 and left colleterial gland ducts, as well as the common colleterial 

 gland duct, have either been emptied of their secretion, or that 

 they have lost their power of secreting. As, however, quite a 

 number of sections were cut through these ducts, and all showed 

 the same structure we are inclined to believe that the cells have 

 given up the secreting function and that the "endothelial or 

 centro-tubular " nuclei have migrated from the position close up 

 against the chitin to one between the cells. To definitely decide 

 this point one would have to work probably with the pupae or 

 larvae. 



The histological change from the common colleterial gland 

 duct to the accessory reservoir is rather abrupt. An outer, irregu- 

 larly branching muscle layer makes its appearance upon the 

 reservoir. The vesicles with their canals and the "endothelial 

 or centro-tubular" nuclei gradually disappear in the sac (Figs. 

 8 and 11). A noticeable change in the epithelium is also apparent. 

 In the common colleterial gland duct, the cytoplasm shows a dis- 

 tinct longitudinal striation toward the basal end of the cells, but 

 near the chitinous intima the cytoplasm becomes granular ; in the 

 accessory sac, however, the cytoplasm is distinctly granular 

 throughout the cell (Fig. 11). The epithelial cells of the colleter- 

 ial reservoir vary in size, owing to the numerous, small, irregular 

 folds into which the wall is thrown. Sharply pointed spines are 

 present in the sac; these are especially numerous near the en- 

 trance of the common colleterial gland duct into the sac, and at 

 the region where the latter passes over into its duct (Fig. 12, sp). 



