GENITAL ORGANS OF THE COW 607 



in thickness. Its lumen, the cervical canal, is spiral, and is ordinarily tightly closed 

 and very difficult to dilate. The vaginal part of the uterus is fused ventrally with 

 the vagina, so that the fornix vaginae is dorsal, and not an aimular space as in the 

 mare. The muscular coat of the uterus is thicker than in the mare. It consists 

 of an external .longitudinal layer and two circular strata. The inner circular layer 

 is about a fourth of an inch (ca. 6 mm.) thick in the cervix. The other layers are 

 continued in the vagina. The mucous membrane of the horns and body presents 

 as a characteristic feature the uterine cotyledons (Cotyledones uterinse).^ These 

 are oval prominences, about a hundred in number, which are either irregularly 

 scattered over the surface or arranged in rows of about a dozen. 



In the non-gravid uterus they average about half an inch or more (ca. 15 mm.) in length, 

 and a little less in width and thickness. During pregnancy they become greatly enlarged and 

 pedunculated. The larger ones then measure about four or five inches (10 to 12 cm.) in length, 

 an inch and a half (3 to 4 cm.) in width, and an inch (2 to 2. .5 cm.) in thickness. The deep face has 

 a hilus at which the vessels enter. The rest of the surface has a spongy appearance, due to numer- 

 ous crypts which receive the villi of the chorion. 



The uterine glands are long and branched. The mucous membrane of the 

 cervix is pale, glandless, and forms numerous folds. The latter are arranged in 

 several series which obliterate the lumen. 

 At the external uterine orifice the folds 

 (Plicae palmatae) form rounded prominences 

 arranged circularly, which project into the 

 cavity of the vagina. There are no glands 

 in the cervix, but a thick mucus is secreted 

 by goblet cells. 



The broad ligaments are not attached 

 in the sublumbar region as in the mare, but 

 to the upper part of the flanks, about a fig. sss.— diagbammatic sagittal section of 

 handbreadth below the level of the tuber p^^t of Urogenital Tract of Cow, 



rrn , . ■ . Showing Suburethral Diverticulum. 



coxae. They contam a conspicuous amount 



of unstriped muscle. The roxmd ligaments 



are well developed, and can be traced distinctly to the vicinity of the abdominal 



inguinal ring. 



The vagina is somewhat longer and more roomy than that of the mare; its 

 wall is also thicker. Its length in the non-pregnant animal is about eight to ten 

 inches (ca. 20-25 cm.); but in the pregnant cow the length increases to twelve 

 inches (30 cm.) or more. The recto-genital pouch of peritoneum extends backward 

 about five inches (ca. 12 cm.) on the dorsal surface, while ventrally the serous coat 

 only extends backward about two inches (ca. 5 cm.). In the ventral wall of the 

 vagina, between the muscular and mucous coats, there are commonly present the 

 two canals of Gartner (Ductus epoophori longitudinales) . When well developed, 

 they may attain the diameter of a goose quill, and may be traced forward to the 

 anterior part of the vagina or even further. They open posteriorly near the ex- 

 ternal urethral orifice.^ 



The vulva has thick, wrinkled labia, and both commissures are acute; the 

 ventral one is pointed, and has on it a number of long hairs; it lies about two inches 

 (5 cm.) behind, and about the same distance below the level of, the ischial arch. 

 The external urethral orifice is four or five inches (10 to 12 cm.) from the ventral 

 commissure. Beneath it is a blind pouch, the suburethral diverticulum, which is 



lAlso known as carunculse uterinse. 



2 These tubes are remnants of the Wolffian ducts, and, like other foetal vestiges, are very 

 variable. Roder states that the right canal was absent in over 52 per cent., the left m only Z2 per 

 cent of the cows examined by him. In some cases they may be traced m the broad liganients tor 

 a variable distance toward the ovary. They are of clinical interest m that cysts frequently form 

 along their course. 



