PATHOGENESIS 299 



a definite and costly activity in the direction of defence. The 

 body has to increase its army of defenders, which means a 

 general (symbiotic) tax and also a certain drain on its vitality, 

 particularly as these phagocytic defenders may easily become 

 spoiled, and from good servants turn into bad and exacting 

 masters (i.e., from scavengers they may become rank 

 parasites). 



" The persistence of the anaphylactic state during so long 

 a period is one of the most remarkable phenomena in Biology, 

 and it is certainly one of the essential factors of individual 

 differentiation." . . . "An anaphylactised individual is 

 no longer the same as a non-anaphylactised individual. Even 

 alimentary ingestion, by the absorption of certain albuminoids, 

 or microbic infections, by the production of toxins in the blood 

 and tissues, may produce anaphylaxis and immunity." (Italics 

 mine.) 



And thus we get the apparently paradoxical proposition 

 that an evil (" certain " albuminoids) introduced into the body 

 produces at the same time disease and " immunity." But on a 

 closer view of the matter we find that this apparent contra- 

 diction is capable of a simple explanation. It is when the body 

 only reacts passively that we get "immunity"; i.e., the 

 reaction involves only a pathogenetic change a kind of latent 

 anaphylactic state without any immediate violent eliminative 

 effort. With an active (acute) reaction to the same stimulation 

 we get anaphylaxis. The two phenomena, therefore, though 

 apparently so different in their results, are never really far 

 apart. 



What seems to puzzle the investigators most in 

 anaphylaxis is the incubation period. But is there really any- 

 thing wonderful in the fact that the carrying out of important 

 symbiotic re-arrangements must take due time ? We have seen 

 that Nature makes no jumps, and that this is so precisely 

 because generally a number of symbiotic correspondences are 

 concerned in every change. 



Further, in order to produce eventually a complete 



