222 THE PRINCIPLES OF IMMUNOLOGY 



change is in the cells may be considered the work of Schultz, Dale, 

 Woods and others with isolated sensitized organs containing smooth 

 muscle. These organs, washed free of blood, responded specifically to 

 the protein with which the animal was sensitized. Of considerable 

 value was the experiment of Pearce and Eisenbrey, who transfused 

 dogs so that the blood of a sensitized dog circulated in the body of a 

 normal dog and vice versa. Under these circumstances the intoxicating 

 dose of the antigenic protein produced symptoms in the sensitized dog 

 with normal blood, but no symptoms in the normal dog provided with 

 blood from its sensitized fellow. Coca confirmed this with the guinea- 

 pig. Although Manwaring and collaborators have found that per- 

 fusion of rabbit heart indicates that anaphylactic shock is entirely 

 humoral, subsequent work of Manwaring and Kusama with perfusion 

 of guinea-pig lungs showed that the cells of the lungs of sensitized 

 animals respond by bronchiolar constriction to perfusion with antigenic 

 serum. They also found that perfusion of normal lungs with a mixture 

 of the blood of a sensitive animal and antigen also produces bronchiolar 

 constriction. None of the experiments so far outlined establishes 

 definitely the parts the cells play, for, as Bell points out, none of these 

 methods has completely removed the native blood from the organs. 

 We know that minute amounts of certain protein poisons are highly 

 toxic, and it may be that the amount of blood left in a perfused organ 

 is sufficient for the production of a humoral poison. Nevertheless, 

 studies of passive anaphylaxis tend to confirm the conception of cellu- 

 lar participation. Weil has pointed out that simultaneous injection of 

 a serum, capable of producing passive anaphylaxis, and its antigen fails 

 to produce symptoms. A certain interval of time must elapse before an 

 animal becomes passively anaphylactic, an interval in which it is pre- 

 sumed the cells either anchor or develop the sensitizing substance. 

 Isolated organs fail to respond to the antigen until a certain time has 

 elapsed. The time element depends to a certain extent upon the mode 

 of injection, but is never less than several hours even with intravenous 

 injection. This fact, in association with the experiments in active 

 anaphylaxis, in vitro, with perfusion and with isolated organs, all tend 

 to support the conception that the participation of the cells is of funda- 

 mental importance in the reaction. Weil has studied further the phe- 

 nomenon of desensitization and finds that the reaction between the 

 cellular antibody and the antigen follows in a general way the Danysz 

 phenomenon (see page 50). By the fractional injection of antigen the 

 substance in the cells takes up the antigen so that subsequent additions 

 of antigen produce little effect. He states that " partially combined 

 cellular antibody manifests a marked diminution in its affinity for fresh 

 antigen." Thus the conception of cellular participation fits the demon- 

 strated facts of passive anaphylaxis. 



Physical Theories. These have been less susceptible to experi- 

 mental proof than other theories because of the limitations of technic. 

 As has been mentioned, Doerr conceived the idea that adsorption of the 

 supposed antagonistic substance of complement by bacteria or precipi- 



