124 Immunity 



The symptoms come on almost immediately. The 

 animal is profoundly depressed, extremely uneasy, pants 

 for breath, and suffers from intense itching of the face. It 

 soon falls, continues to gasp for breath, and dies within an 

 hour. The disturbances in the body of the animal are 

 sufficient to account for the symptoms. Extensive lesions 

 exist, the first to be described by Rosenau* affecting 

 the mucous membrane of the stomach, which appeared 

 ecchymotic and ulcerated. Gay and Southard f found 

 hemorrhages in most of the organs, and believe anaphy- 

 laxis to depend upon the presence, in the blood of the 

 sensitized animal, of a substance to which they have given 

 the name anaphylactin. It seems difficult, however, to 

 imagine how such a substance could remain in the blood 

 throughout the entire subsequent life of the animal. Bes- 

 redka and Steinhardt J found that by the repeated injection 

 of horse-serum into guinea-pigs, the intervals being too short 

 to permit anaphylaxis, antianapkylactin could be prepared. 



Anaphylaxis is not a disturbance of the cells of the body, 

 as some have thought, but is at least in part a disturbance 

 of the composition of the blood, as can be shown by the oc- 

 currence of what is known as passive anaphylaxis. If the 

 blood-serum of a sensitized animal be withdrawn and in- 

 jected into a normal animal of the same kind, it carries the 

 sensitization with it. The new animal, however, does not 

 become sensitized at once, but only after some days, hence 

 it is equally true that the disturbance is not solely in the 

 blood, else why should not the sensitization be immediately 

 present upon the injection of the serum? 



Anaphylaxis may, furthermore, be local. Thus, when 

 certain substances like tuberculin are dropped in the eye 

 there is no effect, but when a second application is made, 

 after some weeks, the eye may be reddened. 



Vaughan has endeavored to explain anaphylaxis by assum- 

 ing that when the strange protein in the blood reaches the 

 cells it is slowly broken down by enzymic action, but that 

 the cells, having once acquired the property of destruction, 

 seize eagerly upon the protein the next time it is offered, dis- 

 integrate it rapidly, and so disseminate throughout the body 



*"Bull. No. 32 of the Hygienic Laboratory," Washington, D. C., 

 October, 1906. 



t "Jour. Med. Reserach," July, 1908, xix, No. i, pp. i, 5, 17. 



J "Ann. de 1'Inst. Pasteur," xxi, No. 2, February 25, 1907, pp. 

 117-127. 



