70 PLANT DISEASE 



laws of nature, and which is proved to be in- 

 correct, as rats which contained an abundance 

 of proteids, remained immune to anthrax, 

 while other rats wanting in proteids died of 

 the disease. 



While scientists of undoubted standing 

 consider there is a chemical difference between 

 the blood of animals immune to and those 

 susceptible to a given disease, I think the 

 evidence is now fairly strong in support of 

 the vital point that pathogenic bacteria can 

 only attack animal life when more or less 

 deficient in haemoglobin, and what follows 

 as a natural sequence, in carbohydrates, fats, 

 and proteids. 



Of course, how far the bacteria can and do 

 produce a further deficiency through the eat- 

 ing up of devitalized carbohydrates, etc., of a 

 blood, and tissues that are already so deficient 

 as to allow them to grow, is another question. 

 It is thought by some that the killing power 

 of blood must be limited. Personally, I think 

 the killing power of a normal blood on patho- 

 genic bacteria is unlimited. 



For instance, there were a few oxen during 

 the rinderpest epidemic in South Africa that 



