The Nodular Venereal Disease 303 



muco-pus is formed in many severe cases. These attrition 

 lesions are also responsible for frequent hemorrhages. 



The biology of the nodular venereal disease has not been 

 satisfactorily determined. Ostertag discovered, in the 

 muco-pus of the vulvae of cows, a streptococcus which he 

 believed to be the essential cause of the disease. He intro- 

 duced the organism, which he had grown experimentally, 



Fig. 90 — A knob-like elevation of the mucosa due to several 

 contiguous nodules. (Thorns.) 



into the vulvae of supposedly sound heifers, and believed 

 that he produced the disease. It is a notable fact that in 

 Ostertag's experiments, while he believed he had trans- 

 mitted the disease to cows and heifers by means of pure 

 cultures, he failed to transmit it to sheep, goats, and swine, 

 although they regularly suffer from it. It is not clear, 

 however, just what he accomplished. Doubt is thrown upon 



