18 Modes of Infection 



mental horse No. 60). It had been watched for four 

 months and a half without being affected. 



Besides, experiments were performed upon several 

 goats and sheep. The results were generally negative. 



Calf. 



40-50 c.c. of the virulent blood was injected into 

 four calves. None of them showed any sign of the 

 disease. Their sera and bile were used for preventive 

 experiments with no effect whatever. 



IV. MODES OF INFECTION. 



In investigating the appearance and spread of infec- 

 tious anemia among horses in Japan, it has been learned 

 that very few cases develop in the stable, while in the 

 pasture it usually spreads with an astonishing rapidity, 

 a great majority or even the entire herd succumbing to 

 it. To take a concrete example. At the Branch Remount 

 Depot, where horses are pastured during the summer, 

 many cases are met with, while in the regiments, where 

 horses are quartered in stables, the disease does not 

 spread out of them, though a few sporadic cases may 

 occur among reserve horses. No cases have as yet been 

 recorded, in which outbreak took place in the districts, 

 where horses are usually kept in stables ; the spread of 

 the disease having been restricted to pasturing districts. 

 What seem to be sporadic cases encountered in breeding 

 or working districts are in reality those introduced from 

 other parts of the country. 



From what has been mentioned above, it can be 

 conjectured that there must be conditions peculiar to 



