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 deferentia), c, f, 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 
