THE BLOOD AND LYMPH AS PROTECTIVE MECHANISMS 251 



of Ehrlich, the alexin is known as "complement," and the sensitizing 

 substance as "immune body. " It is held by this investigator that the 

 complement cannot enter into combination with the foreign substance, 

 or antigen, unless it is attached to it by a mediator, the immune body. 

 In accordance with an earlier suggestion pertaining to the construction 

 of the toxin molecule, it is assumed further that the molecule of the 

 immune body is composed of two groups or haptophores. In accord- 

 ance with their degree of affinity for either the antigen or the comple- 

 ment, one of these groups is designated as "cytophile" and the other 

 as " complementophile. " On account of its "polarity," the immune 

 body has been designated as the "amboceptor." 



To summarize: the antigen (bacterium, blood cell, poison, etc.) 

 cannot be affected by the complement (alexin or antibodies) unless it 

 is prepared for this union by the amboceptor (immune body or sensi- 

 tizer) which, on account of its polar- 

 ity, is capable of becoming firmly 

 anchored to it as well as to the com- 

 plement. Thus, the interaction be- 

 tween the complement and the anti- A c ^ *~, c. 



gen is made possible Only through FIG. 122. DIAGRAM ILLUSTRATING 



the intervention of the amboceptor. RACTION BETWEEN COMPLEMENT C 



. r . AND ANTIGEN A. 



Anaphylaxis. The term anaphy- Am> amboceptor . Cy< Cyt0 phiie 



laxiS (ana : against, phylaxis : protec- and Co, complementophile part of 



tion) was first employed by Richet 1 amboceptor. 

 in 1905 to indicate an increased 



sensitiveness or susceptibility toward infective and other toxic ma- 

 terials. While studying the action of the poison derived from the sea 

 anemone, he found that if a small dose of it, which produced no 

 symptoms upon its first injection, was followed a week or two later 

 by another small dose, the animal became ill and usually died. Thus, 

 the most acute symptoms may follow a dosage which in normal animals 

 produces no effects at all. Inasmuch as a summation effect cannot 

 be held responsible for this phenomenon, because the interval of time 

 between the two successive injections is altogether too long, it must 

 be concluded that this condition of very pronounced susceptibility 

 is developed at some time in the course of this reaction. This deduction 

 implies that certain bodies are called into existence which eventually 

 produce aft acute toxic state. These bodies, however, exhibit a 

 marked specificity, and may be passively transferred to other animals. 

 It has been shown in guinea-pigs that they may be transmitted by the 

 female to her offspring. 



This susceptibility was recognized in reality before Richet applied 

 to it the name of anaphylaxis. Thus, it had been observed that the 

 administration of antitoxins is followed at times by most severe 

 symptoms, giving rise to what Pirquet and Shick 2 have called serum 



1 Soc. Biol., Ixiv, 1908, 847, and Ann. Inst. Pasteur, xxi, 1907. 



2 Wiener klin. Wochenschr., 1902, No. 26. 



