CLOACAL GLANDS OF MALE NECTURUS 451 



The cloacal chamber itself is relatively simple in form, two 

 rather deep ventrolateral recesses being the only modifications 

 of interest in this study (figs. 4, 5, 15, vl.rec). The long, slender 

 papillae, found on the floor and ventral portions of the walls of 

 the chamber, are also present in the ventrolateral recesses. The 

 papillae in the recesses, however, are usually short. Both the 

 internal papillae and the ventral ridges are highly vascular, 

 being permeated by blood channels of considerable size. 



THE WALL OF THE CLOACA 



The wall of the cloaca, especially in its cephalic portion, closely 

 resembles that of the rectum. Mucous and muscular layers are 

 readily recognized (figs. 7, 8). No serous coat, however, is 

 present, but the outermost layer consists of areolar tissue which 

 blends with the connective tissue of the adjacent structures. 

 The presence of large numbers of long tubular glands, which 

 surround and open into the cloacal cavity, has resulted in a 

 great thickening and extensive modification of practically the 

 entire cloacal wall and of the three coats comprising it, but 

 the tunica muscularis has suffered the greatest displacement. 



a. The tubular glands 



The grouping of great numbers of tubular glands in the cloacal 

 wall has resulted in the production of a large glandular mass 

 about the cloaca, which, for the lack of a better term, will be 

 designated as the cloacal gland mass. " This mass lies caudad 

 to the pelvic girdle and occupies a large median ventral area. 

 It is enclosed in a connective-tissue sheath which apparently is 

 a modified portion of the median ventral septum which more 

 caudally separates the hypaxial muscles of the tail (fig. 3, m.v.s.). 



The dorsal portion of the mass extends close to the trunk-tail 

 vertebrae and laterally is bounded in part by the unmodified 

 trunk-tail myotomes and in part by three pairs of slender caudal 

 muscles (mm. ischiocaudalis, caudalifemoralis, and caudalipu- 

 boischiotibialis, Wilder, '12) which are attached to the posterior 

 appendicular skeleton (fig. 2) . Cranially, the dorsal gland mass 

 extends to the posterior ends of the mesonephroi and to the caudal 



JOURNAL OP MORPHOLOGY, VOL. 36, NO. 3 



