THE ORIGIN AND DEVELOPMENT OF GASTRIC GLANDS. 



79 



coming the difficulties caused by the large amount of yolk. The 

 nuclei took a deep blue color, the yolk spherules became a trans- 

 parent orange yellow, while the round cells, so characteristic of 

 this stage in the Desmognathns, stained a deep red. In a larva 

 1 1 mm. total length, although the caudal portion of the stomach 

 is yet undifferentiated, these large, granular, round cells are found 

 at the base of the epithelium (Fig. 18, a). Fig. 20, a, shows 

 one already divided, while in Fig. 20 are gland fundaments in 

 several stages of development. Some extend laterally for about 



FIG. 14. a 3 , gland showing lumen, /.; if., deep indentation with a rearrangement 

 of cells of the epithelium to form the duct. 



30 micra. Here, as in Desmognatlins, the epithelium appears to 

 be made up of several layers of cells, the deeply staining nuclei 

 (Figs. 19 and 20) being arranged at different levels. The cells 

 lining the cavity of the stomach seem to be fewer in number on 

 account of their great distention with yolk, consequently do not 

 present the appearance of alternate layers to such a marked de- 

 gree as was shown for Desmognathns. This orderly arrange- 



