DISEASES OF THE OX AND SHEEP. 643 



branous tube {i in the figure appended below) extending from 

 the labia pudendi to the mouth of the womb {b), and it is 

 situated at the lower part of the pelvis, below the rectum. On 

 its lower surface is the orifice (h) of the urinary bladder {(/). 

 Shortly before the act of parturition, the walls of the vagina 

 become flaccid, and bedewed internally with a copious mucous 

 secretion, whereby the delivery of the foetus is rendered more 

 easy. During the act of coition the intromittent organ of the 

 male is placed within the vagina, and comes into contact with 

 the mouth of the womb, whereby the seminal fluid is trans- 

 mitted into that cavity. The uterus of an unimpregnated 

 animal is small, and especially of diminutive size in the case of 

 a virgin animal, i.e. as compared with a cow which has given 

 birth to several calves. Moreover, the unimpregnated uterus is, 

 for the most part, lodged within the cavity of the pelvis ; but 

 when impregnated it extends in some degree into the abdomen. 

 On each side the uterus is prolonged into a branch called a 

 horn, which, in its turn, is continuous with a tube called the 

 Fallopian tube, near the fimbriated extremity of which is 

 the important organ known as the ovary. From each ovary 

 the ova are passed along the Fallopian tubes into the uterus. 



The uterus or womb, a, is kept in its situation chiefly by 

 means of the broad ligaments /,/; at its anterior part its coats 

 are continuous with the vagina, and posteriorly it is divided 

 into two horns, c, c, to the extremities of which the Fallopian 

 tubes d, d, are attached, and the ovaries, <?, e^ are connected with 

 these Fallopian tubes. 



During the period of gestation^ the os uteri, or mouth of the 

 womb, remains closed ; but at the time of parturition it is widely 

 dilated, aud thus allows a free and open passage from the vagina 

 to the interior of the uterus. The coats of the uterus are three 

 in number, and united to each other by connective tissue. The 

 external or serous coat is smooth and continuous with the lining 

 membrane of the abdomen. This coat gives support to the 

 uterus, and being reflected on each side forms the two broad 

 ligaments. The middle or muscular coat varies considerably in 

 strength and thickness, according as the uterus is or is not im- 

 pregnated, being in the latter case thin and weak, and in the 

 former becoming greatly increased during gestation. 



As the reader will readily understand, the expulsion of the 



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