156 The Alligator and Its Allies 



The ureters open, Fig. 55, d, e, at a moderate 

 distance from each other, into the anterior region of 

 the cloaca (about where the dorsal and lateral walls 

 of this region come together). The genital ducts 

 (oviducts or vasa deferential, c, /, on the other 

 hand, open close together through the ventral wall 

 of the posterior half of the cloaca, just in front 

 of the copulatory organ. 



Into the cloaca, very near the anus, open two 

 glands of fairly large size that Rathke called musk 

 glands. These glands lie outside of the pelvis 

 between the side walls of the cloaca and a large 

 muscle that surrounds this part of the body. 

 They have an oval form and open usually from 

 their anterior end, sometimes just caudad to this, 

 by a short, fairly wide, slit-like opening which has 

 an anteroposterior direction. The walls of the 

 glands are made up of three closely associated 

 layers of connective tissue, the inner one being 

 thrown into folds. Since these layers contain no 

 muscle fibers the secretion of the gland is probably 

 squeezed out by contraction of the circular muscles 

 of the cloaca. Usually the cloacal glands are 

 stretched full by a thick, yellowish mass that smells 

 strongly of musk. 



The part of the cloaca caudad to the pelvic 

 opening has a differently arranged musculature 

 from the more anterior region. It consists of 

 two separate pairs of striped muscles that surround 

 the musk glands on the outer side. The first 



