SPECIFICITY OF DEFENSIVE FERMENTS 99 



defensive measures adopted depend on their nature. 

 In another case two individuals throw themselves 

 brutally one upon the other without any previous 

 choice of weapons ; then any means is good, if it only 

 succeeds in overcoming the opponent somehow. 



One fact must always be kept in mind. When 

 we introduce proteins or peptones and the like into 

 the blood-vessels, these are never pure compounds. 

 Together with the peptones we certainly introduce 

 into the circulation a number of different stages 

 of the decomposition of proteins. Suppose we take 

 the white of an egg, then without doubt innumerable 

 albuminous substances are present, which greatly 

 differ one from the other. We must not forget the 

 fact, that traces of particular substances are quite 

 sufficient to cause the formation of ferments. The 

 cells, on the contrary, set free substances that are 

 probably of a very precise character. 



If we artificially introduce material that is out of 

 harmony with the blood, the animal organism reacts 

 against it with a whole complex of defensive ferments, 

 because our material is always a mixture of sub- 

 stances. It is to a certain degree prepared for all 

 eventualities. It has no actual knowledge of the 

 characteristics of the introduced product. If, at anv 

 point, particular cells exhibit a deficiency of function 

 in respect of their metabolism, then there always 

 appears in the blood plasma, from one moment to 



