588 A. M. REESE 



about 15 cm. total length. The cloacal glands (fig. 15, eg) are 

 considerably more developed than in the preceding stage; 

 the gland on the right side is here seen cut through its median 

 region; the other through the opening of the duct, d, into the 

 cloaca, cl. The body of the gland is elliptical in shape, being 

 somewhat greater along an anteroposterior diameter than along 

 the lateral or the dor so ventral diameters. A slight condensation 

 of the connective tissue around each gland indicates the beginning 

 of the capsules, cp. 



The gland is still a solid mass of cells, though the cells in the 

 central region are somewhat larger and clearer than those around 

 the periphery. The duct, as seen on the left side, is open for only 

 a very short distance. 



Figure 16 represents a section through the cloacal region of a 

 slightly later stage of development than the last. 



The cloacal gland, eg, is here cut through its duct d, which 

 is rather long and narrow. The epidermis, ep, is thrown into 

 complicated folds and is of fairly even thickness throughout; it 

 is directly continuous with the peripheral cells of the gland proper. 

 The periderm, p, is seen along the free border of the epidermis 

 throughout its many folds. It may be traced along the inside 

 of the duct into the gland, where it is lost. Beneath the epi- 

 dermis, in the outer part of the corium, are seen numerous 

 brownish pigment granules, j)g, that are especially numerous 

 around the periphery of the gland proper, in what may be con- 

 sidered the capsule. Outside of the connective tissue part of 

 the capsule is an irregular layer of muscle fibers, m. In the 

 center of the gland is an irregular cavity to be noted in connec- 

 tion with the high-power drawing. A section through the line a-h 

 in figure 16, drawn under a magnification of about 600 diameters, 

 is shown in figure 17. The layer of pigment granules surround- 

 ing the gland is shown to the right, pg; the letter a is placed 

 in the edge of the central cavity of the gland. 



Three regions of cells may be made out, though they are 

 not always sharply difi'erentiated from each other. The outer 

 layer, next to the pigment granules, is composed of rather small, 

 irregular cells, with smaller nuclei than those of the other layers. 



