76 PLANT DISEASE 



The question then is what is the difference 

 between these two soils ? Another significant 

 fact is that in the part of the country where 

 redwater is prevalent, not more than two per 

 cent, of rinderpest infected cattle, prior to the 

 introduction of inoculation, recovered ; on the 

 other hand, where redwater is unknown, of the 

 animals treated with virulent rinderpest blood, 

 with the object of obtaining immunized blood, 

 the percentage of recoveries was as high as six- 

 teen. 



Now I have shown that the blood must vary 

 in quality as the food, hence it is to be expected 

 that food is of better quality on the Karoo 

 than the coast herbage, and that this is so is 

 shown by the fact that Karoo stock of all 

 kinds are healthier than the stock reared on 

 coast farms. 



It is recognized by the Cape experts that 

 there is something wanting in the coast herb- 

 age, but what that something is has never been 

 determined, although we have the fact that 

 sheep having iron on the coast farms are much 

 healthier and suffer less from the various com- 

 plaints affecting these sheep, than farms where 

 they do not have iron. 



