448 ALDEN B. DAWSON 



to be postponed until the limits of the different masses of glands 

 had been definitely determined. Accordingly, the present report 

 deals primarily with the various masses of tubular glands in 

 their relation to one another and to the topography of the cloaca. 

 In a later communication it is planned to describe the variations 

 which occur in the glands during the different seasons of the year 

 and to follow the changes undergone by the several types of 

 cells during the production of secretion. 



Only adult males were used in this study. The material was 

 dissected out and fixed in either formalin, Zenker's fluid, or 

 Bouin's fluid. Serial sections, transverse and longitudinal, 

 were made of the entire cloacal mass, including the cloaca proper 

 and the surrounding glands. The tissue was stained with haema- 

 toxylin and eosin. Van Gieson's picro-acid fuchsin and Mallory's 

 stain for connective tissue. 



LITERATURE 



We are indebted to Heidenhain ('90) for the first detailed and 

 accurate description of the cloaca of a male urodele. He de- 

 scribed three kinds of cloacal glands in the male Triton, the so- 

 called cloacal gland, the pelvic gland, and the abdominal gland. 

 Before this but two types of glands were recognized. Zur Miih- 

 len ('93), who worked on Triton, Salamandra, and Siredon, con- 

 firmed in the main the findings of Heidenhain. Kingsbury 

 ('95), in the course of an extended study of the cloacas of female 

 Diemyctylus, Plethodon, Desmognathus, Amblystoma, and 

 Necturus, discussed, incidentally for purposes of comparison, 

 the structure of the cloacas and the adjacent glands of the males 

 of these different genera. In Necturus, Kingsbury did not make 

 a sufficiently careful study of the glands to enable him to deter- 

 mine whether the abdominal gland is present. 



EXTERNAL APPEARANCE OF THE CLOACA 



The external opening of the cloaca of the male Necturus is 

 simply a longitudinal slit bordered by two inconspicuous lips 

 which, at their caudal ends, give rise to a pair of low rounded 

 papillae (fig. 1, ext.p.). The lips are modified further by 



