382 Veterinary Obstetrics 



wards, if in the base of the cornu, to correspond with the concave 

 side of the uterus. 



As the weight of the fetus increases and bears the uterus 

 downward to the abdominal floor, the position of the arciform 

 fetus becomes unstable because it tends to come to rest, lying up- 

 on its convex dorsal surface, upon the essentially plane abdominal 

 floor. Its position would be equally unstable should it settle 

 against the abdominal floor upon its ventral or concave border, 

 as might occur in the ruminant. Either of the.se positions is so 

 unstable that the fetus tends to revolve upon its long axis 

 and finally come to rest in a more or less lateral recumbent posi- 

 tion. Hence, during the later stages of pregnancy, the fetus is 

 generally found lying .somewhat upon its side along the abdomi- 

 nal floor, where it may be readily felt, through the flank, in our 

 larger animals. 



In ruminants, the downward, forward, and finally backward, 

 curvature of the uterine cornua leads to instability of the fetal 

 position and, as the fetus acquires weight and descends to the 

 abdominal floor, it must assume a stable attitude and, instead of 

 resting upon its ventral surface with its concave border down- 

 wards, must turn upon its side and come to rest upon the abdomi- 

 nal floor. In .so doing, the gravid cornu tends to revolve .slightly 

 upon its long axis. 



The attitude of the fetus is largely determined by its form and 

 the available space for its accomodation. In the cow and mare, 

 the abdominal cavity is not sufficiently long to accommodate the 

 fetus in an extended position and it must con.sequently be doubled 

 up in a way to occupy a minimum amount of space autero- 

 po.steriorly. This condition is most completely fulfilled by the 

 head and neck bending ventralwards .so that the chin comes 

 in contact with the sternum ; the anterior limbs flexed at the 

 elbow and carpus so that the anterior feet rest with their ventral 

 surfaces against the chest, the carpus being in contact with the 

 sides of the head, and the posterior limbs, flexed at the stifle and 

 tarsus, folded beneath the body in approximately the same posi- 

 tion as is observed in sternal recumbency of the adult animal. 



In the multiparous animals, the fetuses rest in a more direct 

 line, there being much less curvature in the long axis, especially 

 toward the termination of pregnancy. The limbs, being shorter 



