DEFENSIVE FACTORS OF THE ANIMAL ORGANISM 253 



One of the most interesting of the cytotoxins, moreover, is nephrotoxin 

 produced by the treatment of animals with injections of emulsions of 

 kidney tissue. 



In all cases it was supposed by those first working with these bodies, 

 that the injection of the sera of animals previously treated with any 

 particular tissue substance would produce specific injury upon the organs 

 homologous to the ones used in immunization. It need hardly be pointed 

 out how very important such phenomena would be in throwing light upon 

 the degenerative pathological lesions occurring in disease. As a matter 

 of fact, however, sera so produced have been shown to be specific for 

 certain organs in a limited sense only. The question of specific cytotoxins 

 has been of especial importance in the case of nephritis, where Ascoli 

 and Figari 49 and others have suggested an autonephrotoxin as the basis 

 of the pathology of this disease. In the hands of Pearce and others, how- 

 ever, the strict specificity of nephrotoxin could not be upheld and the 

 subject is still in the experimental stage. 



Recent experiments by Pearce 50 suggest that at least a part of the 

 local injury to organs exerted by such "cytotoxic" sera may not be 

 due to a specific action upon the organ cells so much as upon the hema- 

 glutinating action of the sera causing embolism and necrosis. 



It is a fact also that most cytotoxic sera are usually hemolytic as well. 

 It is not easy to decide, therefore, how much of the action upon the 

 organs is due to their true cytotoxic properties and how much is attributable 

 to the concomitant action upon blood cells. The extravagant hopes at 

 first based upon cytotoxin investigation, especially in regard to the problem 

 of malignant tumors, have been disappointed, and much is still obscure in 

 regard to the cytotoxins which calls for further research. 



The many points of similarity existing between bacterial toxins 

 and digestive ferments, by animal inoculation, suggested to several 

 observers, the possibility of producing antibodies against the latter. 

 As a result, a number of antiferments have been obtained, chief among 

 which are antilab (Morgenroth 51 ), antipepsin (Sachs 52 ), antisteapsin 

 (Schiitze 53 ), and antilactase (Schiitze). 



The stimulation of antibody formation in the sera of animals is 

 a consequence, therefore, of the injection of a large variety of sub- 

 stances some of them poisonous, some of them entirely innocuous. 



49 Ascoli and Figari, Borl. klin. Woch., 1902. 



60 Pearce, Jour. Exper. Mod., viii, 190(5. 



61 Morgenroth, Cent. f. Bakt., 1899. 

 ^Saclis, Fort. d. Med., 1902. 



Schutze, Deut. med. Woch., 1904; Zeit. f. Hyg., 1905. 



