ALIMENTARY TRACTS AND ADJACENT GLANDS 97 



The remainder of the large intestine, or rectal tract, ex- 

 tended from the colic loops to the anus, and in two speci- 

 mens had a length of about 820 mm. It was not until 150 

 mm. beyond the loops that the contents were formed into 

 the long pellets of typical rodent shape. 



In Neotoma there was situated about 40 mm. posterior 

 to the colic loops a constricted, muscular valve, heavily 

 folded upon the ental surface. In three specimens the 

 total length of the rectal tract was 375, 485, and 505 mm. 

 In Teonoma the length of the rectal tract was 835 and 840 

 mm., in the case of two specimens. 



Anal gland. Surrounding the rectum immediately cra- 

 niad of the anus is a mass roughly spherical but slightly 

 flattened ventrally, which in a male was 10 mm. in diameter 

 and 9 in a female. Enclosing it is a thin layer of fibers of 

 the M. sphincter ani internus, within which are bundles 

 of glandular bodies, bound with fatty and connective tissue 

 extending cranio-caudad. No sacs nor ducts within this 

 mass could be demonstrated. 



In Neotoma the rectal gland measured about 8 mm. in 

 diameter. Upon either side there is a minute duct running 

 parallel with the rectal tract, with a length of 2 or 3 mm. 

 No direct connection with the anus or any other part could 

 be demonstrated. 



In Teonoma the anal gland measured 13 mm. in diameter 

 in a male, and in two females, 11 and 10 mm. respectively. 

 In the male, no sacs could be found in this connection, 

 but a short distance within the glandular mass, upon either 

 side of the ventral aspect of the females, there was a small 

 bulbous sac, between two and three millimeters in diameter, 

 communicating with the adjacent inner wall of the rectum 

 by a short duct, which was demonstrable by means of a fine 

 bristle. The normal contents of these sacs could not be 

 ascertained in the preserved specimens, but their small 

 size, together with the fact that they are not invested with 



