ANAPHYLAXIS 377 



as -^^1^^^ c.c, being sufficient; (2) exactly the same 

 protein must be given on the two occasions ; (3) a certain 

 interval (two or three weeks) must elapse between the 

 two injections. If the protein be given daily, anaphylaxis 

 does not occur. (4) If the animal, as sometimes happen, 

 does not die it may have recovered completely within ten 

 minutes of the second injection ; (5) the mode of death 

 varies in different animals. Guinea pigs and rabbits 

 experience extreme respiratory distress; dogs undergo a 

 violent diarrhoea, with the passage of blood per rectum, a 

 condition resembling cholera. No satisfactory theory has 

 as yet been advanced to explain the nature of anaphylaxis 

 or to show its relationship to immunity. 



From what has been said it will be seen how compUcated 

 is the mechanism by which the body protects itself from 

 bacteria and their chemical products. For further details 

 the reader is referred to works on Pathology and Immunity. 

 The subject is introduced here only to show in a general 

 way how the body adapts itself to its environment. 



