484 



HISTOLOGY 



folds of epithelium are much higher ; the cells on the high curve are all 

 provided with mucous vacuoles. 



Another feature is to be noted here. Besides possessing goblet cells, 

 the epithelium on the folds is evaginated into long tubular glands, the 

 first of which are unicellular glands with their basal portions lying in 

 the connective tissue beneath the epidermis. These are rapidly sup- 

 planted farther out of the groove by multicellular glands which open 



FIG. 454. Outline sketch of one side of the groove in a transverse section of the oviduct of 

 Sycotypus canaliculatus . To the right are seen the simple folds, with occasional unicellular 

 mucous cells. In the middle the heavier folds with both unicellular and multicellular glands. 

 To the left the very large multicellular glands with dotted outlines to mark the regions fig- 

 ured in the next illustration. X 50. 



by narrow ducts, and whose lumen is filled with a blue staining content 

 which still shows mucin reactions. 



Out on the primary nidamental surface, the same structural condi- 

 tions obtain, except that they are exaggerated, so far as the glands are 

 concerned. These are much lengthened, and their straight, parallel 

 bodies form a huge layer, which gives this part its swollen, whitish ap- 

 pearance. Two of these glands are represented to the left of Figure 454. 

 As in the earthworm's clitellum the cells are best defined at the fundus, 

 and farther distally their outer bodies cannot be distinguished in the mass 

 of secretion which fills the lumen. The proximal portions of these glands 



