JIORBID ANATOMY 525 



It is, however, able to live for a long time outside of the body. " 

 In a later article Bang has called attention to the infectious 

 nature of the uterine discharges of the aborted cows. He 

 believes that copulation affords the most favorable opportunity 

 of all for infection. 



The investigations in the United States have failed to 

 reveal the presence of Bang's organism, but instead a variety 

 of B. coli communis has been found by Chester and by Law 

 and Moore. Nocard showed that this organism is able to 

 invade the uterus and provoke the expulsion of the fetus. 



Lignieres, reported by Nocard, found in his investigation 

 that the cause was an infection of the mother with a peculiar 

 organism constantly present in the digestive tract. Prior to 

 this he found the trouble to be caused by the secondary inva- 

 sion of the fetus by various bacteria that are always recognized 

 in variable numbers in multiparous cows. 



The disappointing part of these investigations is that, 

 with the exception of the x\mericans who have found a colon 

 bacillus, the different workers have not verified the findings 

 of each other. Nocard did not believe that abortion was due 

 to a general infection of the dam, because the cow both 

 immediately before and immediately after the act of abortion 

 exhibits no symptoms of disease such as rise of temperature 

 or changes in the urine, blood or milk. Smith found in an 

 epizootic of abortion among mares a bacillus belonging to the 

 hog-cholera group which appeared to stand in an etiological 

 relation to the trouble. The weight of evidence seems to 

 indicate that this form of abortion is caused by some organism 

 that invades the uterus, and which seems to be transmitted 

 from the infected to the uninfected animals by putting them 

 together in stables and in some instances by the use of the 

 same bull. 



The period of inaibation according to Bang is about 10 

 weeks. 



§ 414. Morbid anatomy. The investigations and clin- 

 ical observations reported in this country have not called 



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