18 BULLETIN 106, U. S. DEPARTMENT OF AGRICULTURE. 



If we study trie gravid uterus of the cow (or other ruminant) 

 critically, the provisions against accidental injury to the fetus im- 

 presses the observer as one of the most perfect physiologic arrange- 

 ments to be found in animal life. The fetus of the ruminant is elab- 

 orately protected during intrauterine life. The pregnant uterus lies 

 on a gently inclined plane, the abdominal floor, partly suspended 

 by the vagina and broad ligaments. The fetus gets its nutrient 

 supply, not ordinarily from a diffuse placenta as in the mare, or- 

 zonular placenta as in carnivora, where violence may cause placen- 

 tal detachment and entail fetal death, but instead procures its food 

 supply through 100 or more cotyledons, complex multiple placentae, 

 each usually having a distinct neck, thus leaving an empty space 

 between the uterus and chorion, permitting a to-and-fro movement 

 between the uterine walls and fetal sac in every direction. The 

 fetal security is further insured by its floating free within one and 

 partly within a second sac of fluid. 



As indicated by Table 2, the uteri of over 1,700 pregnant cows 

 and heifers were inspected. Probably very few of them had been 

 shipped less than 100 miles by railroad, many of them hundreds 

 of miles. They had been driven some distance to a railway station, 

 huddled into shipping pens, forced into cars, crowded and jammed, 

 and not rarely got down and were trampled. At every turn oppor- 

 tunity was offered for crowding and jamming. Finally they were 

 goaded into the killing pens, felled with a hammer, and tumbled out 

 on the floor. Certainly they had been subjected to the dangers 

 of mechanical and fright abortion. Yet, in all these cases, no trace 

 of injury to the fetus, fetal membranes, or uterus which might 

 possibly have caused abortion had the animal been allowed to live 

 were seen. While such evidence does not prove the impossibility 

 of accidental abortion in cows, it does indicate that it is not, after 

 all, very readily induced. 



In further search for lesions of accidental abortion in stock-yard 

 cows, two animals were purchased which had aborted in the car or 

 yards and another had expelled a live fetus prematurely. These were 

 killed within a few hours after the occurrence. In none of the three 

 was there a trace of mechanical injury, but lesions were found which 

 are described elsewhere, showing conclusively that the abortion was 

 due, not to mechanical injury, fright, or other accidental causes, 

 but to an infection within the uterine cavity, the evidences of which 

 could not have accumulated in a day or a week. 



All other post-mortem examinations upon recently aborted cows, 

 so far as found recorded, have uniformly shown, beyond question, 

 that infection, not accident, was the essential cause of the death and 

 expulsion of the fetus. No case of alleged accidental abortion in 



