592 A. M. REESE 



Figure 18, B, represents a lateral view of the cloacal gland of 

 a 1.6-meter caiman, removed from the body and freed from the 

 surrounding mass of muscle and connective tissue. It is, like 

 the preceding 80-cm. stage, distinctly retort shaped, the duct, 

 d, representing, of course, the neck of the retort. The region 

 of the gland from the duct to the dotted line has a dark appear- 

 ance, as though there were black tissue showing through the 

 capsule ; the other half of the gland has a pale yellow color. The 

 gland has a distinct musky odor and an oily feel, and when some 

 of the 80 per cent alcohol in which the gland is preserved is 

 allowed to evaporate on a slide, a film of oil droplets of various 

 sizes (fig. 25) is deposited upon the glass. 



A small segment, from the capsule inward, was cut from the 

 middle region of this gland and was sectioned and stained. 

 Figure 26 represents a small portion of this segment, shown 

 under low power, chiefly to indicate the positions of three typ- 

 ical regions which are shown in figures 27, 28, and 29 under higher 

 magnification. 



Figure 27 shows a section through the capsule, cp, and the 

 adjacent cells, region 1. The capsule consists of outer and inner 

 layers of connective-tissue fibers, ctj on either side of a fairly 

 sharply defined layer of involuntary muscle fibers, w. It is 

 generally stated that' the capsule of the cloacal gland has no 

 muscular layer and that the secretion of the gland is expressed 

 by the muscles of the cloacal region. The gland cells in this 

 region, particularly those nearer the capsule, are small and 

 irregularly arranged, with small nuclei and quite indistinct cell 

 walls. No arrangement of cells comparable to the basilar cells, 

 described in connection with the dorsal gland (fig. 11), can be 

 determined. Strands of connective tissue from the capsule 

 penetrate the gland among these cells at intervals, but are not 

 shown in the figures. 



In region 2, figure 28, the cells are much larger, as a rule, than 

 in region 1, usually several times as large. The nuclei also are 

 variable, but generally larger, and the cell walls are very sharply 

 defined, almost like those in some plant tissues. The radiating 

 strands, st, noted in connection with the preceding stage are not 

 noticeable here. 



