The Muellerian Duels 29 



bond between the mother and fetus during the span of preg- 

 nancy. The uterine mucosa is presumed to exert important 

 bactericidal powers, but a majority of uteri of cows, both 

 pregnant and non-pregnant, contain bacteria, several of 

 which appear competent to induce important disease (steril- 

 ity, abortion). In the non-gravid uterus, as is common 

 with distensible hollow organs, the mucous membrane is 

 thrown into numerous longitudinal folds, which facilitate 

 prompt and extensive dilation of the cavity without violence. 



The muscular coat consists of two somewhat differentiate 

 groups of longitudinal and circular pale muscle fibers which 

 increase during pregnancy in size, activity, and, it is be- 

 lieved, to some extent in number. The proportion of the 

 longitudinal to the circular fibres varies. 



The peritoneal layer of the uterus, which is derived from 

 that of the abdominal walls, envelops the organ completely 

 except at the points of continuity with the oviducts and 

 vagina and the interstice between the two peritoneal sheets 

 of the broad ligament at their points of uterine attachment. 



The uterus is retained in position by its broad ligaments 

 and by its continuity anteriorly with the oviducts and pos- 

 teriorly with the cervix. The round ligament of the uterus, 

 arising from the skin, or dartos, in the region normally 

 constituting the fundus of the scrotum in the male, and 

 passing up through the inguinal canal and abdominal ring 

 and thence to the cornu, or oviduct, is functionally of scant 

 interest as a ligament of fixation. The uterus is located 

 immediately beneath the rectum, with its two cornua pass- 

 ing obliquely outward and forward on either side. 



The uterus of the mare, with its cornua, constitutes a 

 somewhat crucial organ : the horns leave the body laterally 

 at right angles or somewhat recurved. The uterine body 

 is oblong, flattened somewhat from above to below, varying 

 from 5 to 8 inches in length and ±1/2 to 2 1 /? inches in width. 

 Anteriorly, the cavity of the uterine body of the mare is 

 continuous with that of the two cornua, without a distinct 

 line of demarcation beyond an abrupt turn at right angles 

 or slight recurvation to its long axis. Each cornu is much 



