PROTEIN SENSITIZATION OR ANAPHYLAXIS 239 



mined by the chemical structure of the protein molecule. 

 We hold this to be true of all specific biological tests for 

 proteins, whether they be agglutination, precipitin, lytic, 

 complement deviation, or anaphylactic tests. The chemical 

 structure of the protein molecule determines all of these. 

 The form and function of every cell is determined by the 

 chemical structure of its constituent proteins. That the 

 sensitizing agent in the protein molecule resides in its 

 secondary groups is shown by: (a) The fact that sensitiza- 

 tion is within limits specific; (6) The fact that the residues 

 left after stripping off these secondary groups by proteo- 

 lytic digestion or by the action of dilute bases and acids, 

 do not sensitize. Peptones, polypeptids, amino-acids, and 

 the protein poison do not sensitize to either themselves 

 or to the unbroken proteins from which they have been 

 derived. 



The Animal. Guinea-pigs give the most striking results. 

 They are easily sensitized and anaphylactic shock develops 

 promptly and violently. It is worthy of note that the 

 work of Besredka in France and of Rosenau and Anderson 

 showed great difference in the reaction in guinea-pigs 

 in the two countries. In this country practically 100 per 

 cent, of the animals sensitized to horse serum die on the 

 second injection, made intraperitoneally ; while in France 

 the highest percentage of fatality following the same pro- 

 cedure is 25. It was at first supposed that this difference 

 is due to the race of horse supplying the serum, but Rosenau 

 and Anderson, using Besredka's serum, obtained the same 

 results as with the American serum. The same investi- 

 gators say that the difference is not due to races of guinea- 

 pigs. In our work with egg-white we noted a much higher 

 percentage of mortality with short-haired, smooth-coated 

 animals than with the long, curly-haired ones. 



Doerr and Russ, 1 using ox serum, with the second dose 

 constant at 0.2 c.c., found the following comparative 

 results by varying the sensitizing dose, both doses being 



1 Zeitsch. f. Immunitatsforschung, ii, 109; ibid., iii, 181. 



