288 SYMBIOGENESIS 



Prof. Richet thinks that the comparison between 

 anaphylaxis and heredity opens a wholly new and unexplored 

 field ! So it does, provided we recognise that the deleterious 

 effects of in-feeding begin to have cumulative and hereditary 

 effects long before an actual outbreak of acute disease, and 

 that the predisposition originates with faulty parental feeding 

 habits, a transmitted diathesis. 



The real differences between individual susceptibility and 

 true anaphylaxis, it seems, cannot be strictly defined, i.e., we 

 may be dealing only with different degrees of susceptibility to 

 poison ! 



Anyhow, "it is possible by physiological methods to 

 modify the reactions of an animal in such a way that 

 immediately after the injection of a poison it reacts just like an 

 anaphylactised animal " ; i.e., an animal may show its reaction 

 to poison at once instead of requiring a definite incubation 

 period in which to deal with it. 



What are the particular " physiological " methods 

 which lead an animal to a sudden and violent reaction like that 

 usually witnessed in one that was first "sensitised" by a 

 poison (anaphylactised) and thus given time and opportunity 

 to mature such a reaction? 



" I have induced this condition," says Prof. Richet, " by 

 means of profuse haemorrhage. A dog which had been bled 

 4'3 per hundred of its weight (never fatal in a dog) was given 

 O'OOl c.c. of crepitine, an amount never fatal in a normal dog 

 even at the end of a month. Immediately its condition became 

 miserable, resembling that of an anaphylactised dog. Here it 

 would be absurd to speak of anaphylaxis; rather is it an 

 instance of increased sensitivity, for which the previous 

 haemorrhage may be held responsible. It is clear that in 

 certain states which we do not understand some individuals are 

 more sensitive, although there is no question of spontaneous 

 anaphylaxis." (Italics mine.) 



The experimenter thus first diminished the vitality of the 

 dog through bleeding and, though, as he avers, not fatally so, 



