206 TOXINES AND ANTITOXINES. 



while it had hardly any action upon human blood, and none at 

 all upon the blood of dogs, guinea-pigs, rats, hens, geese, and 

 pigeons. 



LAU (loc. cit.) supplemented these results by others, in which 

 he observed agglutination in the blood of the perch, but none in 

 that of the cat and hedgehog. Neither investigator found any 

 agglutination in the case of rabbits' blood, but there was a haemo- 

 lytic action. Crotine is stated not to possess the power of pro- 

 ducing a precipitate with serum. It has an equal agglutinating 

 action upon the washed erythrocyfces and stroma. Oxygen is 

 said to promote the action of crotine, while antitoxic substances 

 that restrict its influence are present in the serum. It has no 

 influence, or at least a very much slighter one than ricine, upon 

 pus cells and other cells, but, on the other hand, it causes milk 

 to coagulate. EHRLICH and MoRGENROTH, 1 and also JACOBY^ 

 have studied the mode of action of crotine hsemolysine with the 

 aid of the modern methods of investigating haemolysines. 



MORGENROTH proved that crotine was a haptine by the fact 

 that he was able to produce an immune serum in goats. 



JACOBY found no support for the view that crotinolysine con- 

 sisted of an amboceptor and complement, and was inclined to 

 regard it as a haptine of the first class, like ricine. 



By means of his experiments with partial saturation (c/. 

 General Part), he has established that crotine must possess a 

 complex constitution like that of diphtheria toxine, but it is 

 noteworthy that very small doses of antitoxine increase the toxic 

 action to a slight extent, since they eliminate the absolutely non- 

 poisonous prototoxoids, which otherwise combine with part of 

 the cell receptors, and thus reduce the toxic power. Then very 

 rapidly, with the increase in the doses of antitoxine, the bulk of 

 the poison is neutralised, and after that comes a wide zone with 

 very slight affinity i.e., the toxones which no longer effect 

 complete haemolysis, but with which JACOBY was yet able to 

 produce immunity. 



As is the case with other blood poisons (see, e.g., Arachno- 

 lysine), insusceptibility and lack of power to combine with the 

 poison also go hand-in-hand here. The blood-corpuscles of dogs 

 and guinea-pigs do not combine with any trace of crotine. 



A thermostable anticrotine, which apparently restricted the action of 

 crotine in accordance with quantitative laws, was found by JACOBY in the 

 extract of the mucous membrane of the stomach. 



iEhrlich, "Verh. Ges. Charity-Aerate, Feb. 1898," Berl klin. Woch., 

 1898, No. 12. 

 2 Jacoby, "Ueber Crotin-Immunitat," Hofm. Beitr., iv., 212, 1903. 



