24 PARASITES IN GENERAL 



less to an injurious and poisonous state. The foreign substance 

 is merely the trigger which, so to speak, ignites or explodes the 

 charge contained within the blood vessels." In the case of so- 

 called " specific anaphylaxis," in which anaphylactic poison- 

 ing results from the injection of particular kinds of organisms 

 or toxins, as, for instance, the shock that results from typhoid 

 vaccination of a person already immune to typhoid, the specific 

 action is due to the production of ordinary anaphylatoxin by the 

 interaction of an antibody, already developed, with the antigen 

 which produced it. To cite another example, it has been shown 

 that injection of the ground bodies of ox warbles into cattle 

 which have been infested by even small numbers of these mag- 

 gots produces an anaphylactic shock. According to the theory 

 of Novy and De Kruif this would be explained as follows: the 

 presence of warbles in the cattle causes the production of anti- 

 bodies in the blood. Injection of warbles places large quantities 

 of the antigen in the blood. Interaction of antibody and antigen 

 produces a substance which transforms the poison matrix al- 

 ways present in the blood into anaphylatoxin, and the latter 

 produces the symptoms of poisoning. The theory has recently 

 been advanced that the severe effects of the bites of some blood- 

 sucking arthropods, such as ticks, mites and blackflies, in which 

 the first attacks are much milder than the later ones, may be 

 in the nature of anaphylactic reactions. According to the 

 theory of Novy and De Kruif, these effects would be produced 

 by the formation of anaphylatoxin as the result of an interaction 

 of an antigen in the arthropod's salivary secretions with an anti- 

 body already formed in the bitten individual. 



Novy and De Kruif point out the possibility that substances 

 inducing the formation of anaphylatoxin may be produced in a 

 normal individual by some peculiarity of diet, exposure, obscure 

 infections, etc., and while the amount of poison thus produced 

 may not be sufficient to cause an acute anaphylactic shock, it 

 may be sufficient to cause a subacute or chronic form of poison- 

 ing, leading to anemia, cachexia, etc. The significant state- 

 ment is also made, and is apparently well supported, that a con- 

 siderable part of the toxic effects of infectious diseases is in all 

 probability due to the formation of anaphylatoxin. The so- 

 called " endotoxins " supposed to be liberated in the blood by 

 the disintegration of bacteria and other parasites possibly do 



