128 APPLICATION OF METHOD IN INFECTIOUS DISEASES 



pre-eminent importance. It is not the bacteria alone, 

 and the so-called toxins, that have to be considered in 

 the whole question of immunity reactions, but most 

 probably the intermediate products of their meta- 

 bolism, as well as certain decomposites which are, 

 at any rate partly, formed quite outside the cells in 

 question. And, above all, \ve have to consider the 

 structure of the organism. The host directs its 

 struggle, not only against the living micro-organism, 

 but also against the particles which appear with the 

 decay of the dead organism, and more particularly 

 against the intermediate products which originate 

 during the preparation of the nutritive medium. The 

 organism attacks every point with its ferments, and 

 tries to decompose or reconstruct anything that is 

 disharmonious with its structure or configuration, or 

 even its physical properties. The more it succeeds 

 in this respect, the more does it deprive the micro- 

 organisms of the conditions required for their 

 existence, and protect its own cells against the 

 injurious action of these substances. 



We come, then, to the conclusion, that at least one 

 part of the means of defence, possessed by an organ- 

 ism against infections of any kind, depends on its 

 power of liberating ferments, which attack the dis- 

 harmonious substances be they by-products or 

 end-products of metabolism, or products of cellular 

 disintegration and deprive them as quickly as 



