284 Diseases of the Genital Organs 



and abortion in a herd was parallel to the virulence of the 

 nodular venereal disease. All deductions were based upon 

 the presence or absence of given lesions. 



Bacteriology was making enormous strides. Wherever 

 a distinct lesion was recognized, search was made for a 

 bacterial invader as a cause and efforts were directed to- 

 ward the experimental transmission of the disease. Oster- 

 tag, after a brief bacterial study of the disease, reached the 

 conclusion that it was due to a streptococcus. No one seri- 

 ously attempted to cause sterility or abortion experimentally 

 by the artificial transmission of the disease. Wider ob- 

 servation showed the lesions to be essentially omnipresent. 

 Many began to doubt that these lesions could be the cause of 

 sterility and abortion, since in that case the bovine species 

 would be wiped out. Many were not ready to believe 

 (though abundant examples exist) that an infection can ex- 

 ist generally and only now and then prove serious. 



Ten years after the interesting observations of Isepponi, 

 Bang made his famous discovery of the B. abortus and sur- 

 passed in the plausibility of his teachings by experimentally 

 inoculating pregnant animals which were assumed to be 

 free from the B. abortus infection. Some of the experiment 

 animals aborted and from the uterus of the cow or the 

 stomach of the abort Bang recovered a bacterium which, it 

 was assumed, was the lineal descendant of the bacteria in- 

 troduced. The teachings of Bang quickly gained a promi- 

 nent place. In the enthusiasm which grew up, sterility was 

 essentially forgotten or assigned a secondary place. The 

 nodular venereal disease was promptly overshadowed as an 

 important genital infection. The B. abortus occupied the 

 field of thought in connection with genital diseases, and all 

 else was consigned to oblivion. 



During the two past decades little has appeared in veteri- 

 nary literature concerning the nodular venereal disease, 

 and that little has been generally ignored or roundly con- 

 demned. The disease is still described in recurring edi- 

 tions of the foremost treatises upon veterinary medicine,, 

 rather as a matter of habit than because of any living in- 



