Schroeder (12) carried out investigations to ascertain the fre- 

 quency \\'ith wliicli bulls react to abortion tests, and the frequency 

 Avith which lesions chargeable to al)ortion bacilli occur in the re- 

 productive organs of reacting bulls. Studies were also pursued 

 which he states conclusively prove that bulls with infected repro- 

 ductive organs may expel abortion bacilli with the seminal fluid. 

 In the first two mentioned investigations 325 bulls from a Wash- 

 ington abbatoir were tested, and slaughtered upon reaction. "Ap- 

 proximately ten per cent of the bulls reacted, and approxi- 

 mately ten per cent of the reacting bulls showed lesions of the 

 reproductive organs from which abortion bacilli were isolated.'* 

 The value of these studies, he emphasizes, lies not in " that they 

 give us a measure of the proportion of bulls that react positively 

 to abortion tests or the proportion of reacting bulls that are car- 

 riers of abortion bacilli," but in " the fact that they show that 

 abortion bacillus disease of tlie bull's reproductive organs is not a 

 whoU}' unique affection which practically may be ignored, but an 

 important condition that must be taken into account in our efforts 

 to combat infectious abortion, since it has been proved to be asso- 

 ciated with contamination of the seminal fluid." In discussing 

 the method by which infected bulls transmit the organisms to 

 cattle, he believes that leakage of semen from the penis, or vaginas of 

 cattle after service, contaminates the food which subsequently gains 

 entrance to their digestive tracts. As the result of a series of 



experiments, he states: " the results fail to justify in the 



least degree the assumption that cows are infected with abortion 

 bacilli via their vaginas or uteruses at the time of copulation, or 

 that the bull, through copulation, is an agent in the spread of 

 abortion disease." 



The work so far alluded to, has been limited to infection with, 

 and the transmission of, Bart, ahortnm and the lesions associated 

 with such infection. The last mentioned author, however, states : 

 "A search for other specific causes of al)ortions among cattle 

 has not been neglected, and bureau investigators could relate at 

 great length stories similar to those which investigators have told 

 about microorganisms isolated from the products of abortions and 

 the uteruses of cows that have aborted. Bacilli of various kinds, 

 different types of micrococci, and spirilla or vibrio have been found 

 repeatedly ; but when their pathogenicity has been tested in accord- 

 ance with widely recognized and accepted and required bacterio- 

 logical standards, not one shred of evidence has been obtained to 

 prove them true etiological factors of bovine abortions. What role 

 such microorganisms may have as causes of the sequellae of in- 

 fectious abortions, and of other, possibly, independent, abnormal 

 processes in the reproductive organs, is far from clear and merits 

 careful study." Iladley (5) mentions the fact that: " Unques- 

 tiona1)]y the male often ])ecomes infected with the germs that 

 produce the various secondary' diseases in the female, Avhich are 

 properly classed under the more inclusive term 'abortion dis- 

 ease.' " Also, speaking of the rarity with which the bull acquires 



