360 



INFECTION AND IMMUNITY 



0.5 c.e. or preferably more, and twenty-four hours later an injection 

 of the specific antigen that is, the protein used for sensitization 

 is given. The animals so treated show typical symptoms of hyper- 

 susceptibility and often die. 



Simultaneous inoculation of the two substances, either mixed or 

 injected separately, does not produce the same effect. A fact, 

 observed by Otto, is that the serum of guinea-pigs who have been 

 given the sensitizing or first injection will confer passive anaphylaxis 

 on the eighth or tenth day after injection, before the animals them- 

 selves show evidences of being actively hypersensitized. It is also 

 true that occasionally the serum of antianaphylactic animals will 

 possess the power of conferring passive anaphyiaxis. 



It is by means of the passive method of sensitization that the 

 relations between anaphylaxis and antibodies have been most suc- 

 cessfully studied. Doerr and Russ 30 showed that the power of a 

 serum to convey anaphylaxis passively depended directly upon its 

 contents of specific antibody. It was then' shown by Nicolle, 31 

 Otto, 32 and others, that a sharp reaction can be produced by this 

 method only when a distinct interval not less than four to six hours, 

 was allowed to lapse between the injection of the antibodies and 

 the injection of the antigen. This may be taken as an axiom for 

 all cases in which the antigen is an unformed protein in solution. 



It was also shown by Weil 33 that passive sensitization could be 

 conferred by the injection of precipitates formed in the test tube 

 between an antiserum and its antigen, a thing which we can now 

 well understand in view of the knowledge we have of the dissociation 

 of antibody from such precipitates. 



Anaphylaxis may be transmitted passively by inheritance. Thus 

 the young of anaphylactic guinea-pigs show hypersusceptibility, 

 irrespective of whether the mother became hypersusceptible before 

 or after the beginning of pregnancy. Such anaphylaxis has no 

 reference to the condition of the father, and is not transmitted by 

 the milk. 



The nature of these anaphylactic antibodies has aroused much 

 discussion. By many observers they are regarded as special 



80 Doerr and Russ, Ztschr. f. Immunitatsforsch., 1909, iii. 

 "Nicolle, Bull, de PInst. Past., 1907, v. 



32 Otto, Das Theobald Smithsche Phaenomenon, . etc., von Leuthold Gedenk- 

 schrift, 1905, i. 



33 Weil, Jour, of Immunol., 1, 1916, 19. 



