PATHOGENESIS 313 



experiments under the head of anaphylaxis may be viewed as 

 providing striking tests of this important evolutionary law. 

 They shqw by their results that, though an in-feeding mode is 

 possible for a while under reliance upon symbiotics with 

 apparent impunity, the blood is in reality all the time obliged 

 to protest against the biological unsuitability of such food, and 

 to make many even pathogenetic concessions, whilst all the 

 time the eliminative powers are being taxed to breaking point 



It seems that sometimes anaphylactic phenomena are inter- 

 changeable. If one of two poisons is used for "sensitising," 

 the other may be used for " intoxicating," which again seems 

 to indicate that the first method has induced a kind of patho- 

 genetic convergence; i.e., the body is now predisposed to 

 reaction, and various kindred poisons when super-injected 

 are now capable of precipitating the identical reaction, of 

 pulling the trigger of reaction, as it were. " The anaphylactic 

 phenomena, however, are most often rigorously specific, so 

 much so that it is possible to distinguish anaphylaxis brought 

 about by ox, sheep, dog, or human blood; by cow's, mare's, or 

 human milk, etc., with such a degree of accuracy that this 

 process of diagnosis might be made use of in forensic 

 medicine." 



As a rule, then, the blood makes a definite and pro- 

 nounced protest against the introduction of every biologically 

 unsuitable and antagonistic substance, and that this is so is 

 significant also as an object lesson regarding feeding, the 

 reactions there being merely much slower. 



In the case of sera acting as anaphylactising substances 

 " following stronger doses, anaphylaxis takes a longer time 

 to appear." I should explain this again as meaning that with 

 strong doses a considerable amount of pathogenetic activity for 

 '" alloy "-formation is required, and that this necessitates a 

 considerable period of incubation. 



Prof. Eichet interprets it thus : 



It seems that anaphylaxis can only develop when all the prepara- 

 tory substance has disappeared. 



