12 Pathogenesis. 



bacteria-proof. From this we can infer that the disease 

 is caused by one of the ultramicroscopic organisms. 



That the virus is present in the blood and various 

 viscera was demonstrated by the following experiments. 

 An animal of quite advanced case was killed and ten 

 different organs were taken out of its cadaver (blood, 

 spleen, liver, kidneys, spinal cord, lymph-glands, salivary 

 glands, muscles, lungs and bone-marrow) Each organ was 

 injected into two healthy individuals, thus using twenty 

 experimental horses altogether (Experimental horses-extra 

 series Nos. 9-18, 21-30). Every one of them became 

 affected in the course of from eleven to fifteen days. 

 Urine and milk of a patient were separately injected 

 into healthy individuals (Experimental horses-extra series 

 Nos. 1-3). They also showed typical symptoms of the 

 disease. The conclusion can be drawn from the above 

 expriment that the virus is excreted in urine and milk. 

 We could not, however, detect it in the faeces and sweat 

 of sick horses. 



If blood be drawn from a patient during a febrile 

 attack and even a small quantity of it, say 5 c.c, be 

 injected into a healthy horse, the latter thus becomes 

 affected. A horse receiving intravenously 0.5 c.c. of serum 

 diluted with saline solution showed characteristic symp- 

 toms of the disease after an incubation of 17 days. 



According to the results obtained by the experiments 

 performed upon 16 horses, the first febrile attack came 

 from 9 to 29 days after a subcutaneous inoculation of 

 20 c.c. of the patient's blood. In one instance, in which 

 a horse received 100 c.c. of the patient's blood subcuta- 

 neously, the latent period was only three days. 



Healthy horses (Experimental horses Nos. 510-630) 

 receiving patient's blood with 2.5°/o-5<'/o of sodium tau- 

 rocholate remained unaffected. This seems to indicate 



