7i8 Veterinary Obstetrics 



If the embryo commences to form in the uterine cornua, with 

 its ventral surface directed toward the os uteri, and the fetus 

 curves ventrally, it would naturally follow that, as it attains 

 weight, the central portion of its body would tend to drop 

 downward, while its two extremities would point upward toward 

 the oviducts. Later the fetus would tend to descend until the 

 convex dorsal surface would come in contact with the abdominal 

 floor and thereby assume an unstable position. Since the anatom- 

 ical conditions prevent its revolving upon its long axis in the di- 

 rection of the pelvis, it may acquire stability only by its ex- 

 tremities passing forward and downward to come to rest upon 

 the abdominal floor. In accomplishing this movement, the fetus 

 revolves upon its long axis ; and in doing so its dorsal surface 

 turns toward the birth canal, pushing the uterine floor back- 

 ward beneath the vaginal floor, and stretching the roof of the 

 vagina forward. In this transverse position, the fetus must 

 necessarily drop well forward and remain wholly in front of the 

 pubis, thus stretching and elongating the vagina to a remarkable 

 degree. We have attempted to indicate this change in the 

 position of the fetus in Figs. 120 and 121. 



Symptoms. This anomaly in development naturally passes 

 unobserved during the entire period of gestation, and is not dis- 

 covered until an examination is made in order to determine the 

 cause of dystokia. The symptoms are then unique and diagnos- 

 tic. Before the obstetrist is called, the os uteri has become 

 dilated, the water-bag has appeared and ruptured, and probably 

 some of the fetal membranes lie in the vagina or protrude from 

 the vulva. The labor pains are weak in character. The fact 

 that no portion of the fetus, or at least no considerable portion 

 of it, can usually be forced into the vagina, tends to inhibit any 

 well marked expulsive efforts. Such would necessarily prove 

 futile, and dangerous to the integrity of the uterus. 



When the obstetrist inserts his hand, he is first struck by the 

 extremely elongated and narrowed vaginal passage, which is 

 nearly twice its ordinary length, although very much decreased 

 in its transverse diameter. No os uteri or cervix is distinguish- 

 able as such. If the obstetrist follows the roof of the vagina, 

 the hand glides along it almost as far as the arm can reach ; or 

 perhaps he cannot reach the anterior end of the roof, where it 



