882 EXPERIMENT STATION RECORD. t Vol. 36 



tain themselves in the bodies of nonpregnant cows elsewhere than in their 

 udders. 



Investigations of seemingly vigorous, healthy calves produced by cows with 

 infected udders have shown that such calves may harbor abortion bacilli in 

 their stomachs and gastro-hepatic lymph glands, but invariably when the calves 

 were infected the afterbirth and the uteruses of their dams were also infected 

 with the disease. 



The authors find that the agglutination test for abortion disease is fully as 

 reliable as the complement-fixation test, but far less complex, and hence, in the 

 hands of those who have many and varied duties, more reliable. The introduc- 

 tion of abortion bacilli into the udder through the teat, though a method of 

 injection was used which almost certainly precluded mechanical injury, posi- 

 tively infected it and caused the gradual development of agglutinating power 

 for suspensions of abortion bacilli in the blood serum. The passage of abortion 

 bacilli from the udder to the uterus is held to be an experimentally demon- 

 strated fact. 



The present status of the abortion question, A. Eichhorn and G. M. Potteb 

 {Jour. Amer. Vet. Med. Assoc, 50 {1916), No. S, pp. 295-320) .—The data given 

 in this paper, presented at the meeting of the American Veterinary Medical As- 

 sociation, at Detroit, Mich., August 22, 1916, are based upon investigations car- 

 ried on by the U. S. Department of Agriculture. 



In discussing the difiiculties met with in their investigations of contagious 

 abortion of cattle, reference is made to the new type of the organism which 

 occurs in the milk of certain cows, recently described by Alice Evans (E. S. R., 

 35, p. 675), and to which the name Bacillus abortus lipolyticus is given because 

 it decomposes butter fat. This type has failed to react to the agglutination 

 and complement-fixation tests and feeding and inoculation tests have also been 

 inconclusive. A strain of B. abortus from pathogenic sources after having 

 grown for 9.5 months in a medium containing mills fat acquired the same fat- 

 splitting property. 



In several herds where abortions have occurred occasionally repeated sero- 

 logical tests have failed to demonstrate the presence of B. abortus. Whether 

 these organisms play a causative role in such cases; whether they are attenu- 

 ated forms of the pathogenic variety which have lost some of their character- 

 istics as they acquired the fat-splitting property, and if so, whether under cer- 

 tain circumstances they may not regain their pathogenic properties ; and 

 whether they are detrimental to human health are questions that remain to be 

 determined. 



The authors' experience leads them to believe that there may be some organ- 

 ism of which nothing is known at the present time that may eventually be found 

 to cause abortion in at least part of those cases (some 5 per cent) now recog- 

 nized as nonspecific abortion. 



In a discussion of immunity the authors state that even among young cows 

 abortion occurs but once in much more than 50 per cent of the cases. Whether 

 this be called immunity or by some other name there is unquestionably some 

 protective agency that for all practical purposes must be recognized as an ac- 

 quired resistance against the disease. In a large herd at Washington, D. C, 

 where investigations have been carried on, abortions were frequent while new 

 eows were being purchased and susceptible material thus added, but as the 

 practice was discontinued and the calves born in the herd were raised the dis- 

 ease progressively decreased, until at the present time abortion is rare and a 

 definite herd immunity seems to have been established. 



The authors find that serological tests are not infallible, due to the fact that 

 both the infected animals and the immune ones which no longer harbor the 



