IMMUNE OPSONINS AND BACTERIOTROPINS 103 



is possible, but that auto-antibodies, viz., antibodies against the 

 cells of the same animal which furnished the cells, can also be pro- 

 duced. The demonstration of this possibility is, of course, most 

 important from the standpoint of animal pathology, for it raises 

 the question whether some of the symptoms occurring in diseases 

 in which active cellular destruction is known to occur, or even some 

 of the pathological lesions, may not be the outcome of the formation 

 of autocytotoxins. Observations in this direction are as yet too 

 meager to warrant any far-reaching conclusions. I would merely 

 call to mind the now well-established fact that the serum in various 

 pathological conditions has been shown to be hemolytic for the 

 red cells of other individuals, and while there is evidence that the 

 cells of the same individual (i. e., the one furnishing the serum) 

 are more resistant, the thought naturally arises, whether the anemia 

 which is so frequent in the very diseases in which autohemolysins 

 have been demonstrated, viz., syphilis, tuberculosis, and cancer, 

 may not in a measure be due to the action of such antibodies. 



It has been argued that if such antibody formation actually did 

 take place the harm done would be progressive, unless indeed an anti- 

 autocytotoxin formation in turn were to occur. The production 

 of such bodies also has actually been demonstrated by a number 

 of observers (Bordet, Miiller, Ehrlich, and Morgenroth), and it has 

 been shown, moreover, that these substances are of the nature of 

 anti-amboceptors. Of their role in the animal organism, however, as 

 well as that of the auto-antibodies themselves, our knowledge is still 

 most imperfect and a discussion of the various possibilities would at 

 present amount to little more than a philosophical discourse. 



Immune Opsonins and Bacteriotropins. Further studies have shown 

 that in addition to the various types of antibodies which we have 

 considered so far there are still others. 



We have had occasion to point out in a previous chapter that in 

 the course of various infections, substances appear in the blood which 

 prepare the corresponding organisms for phagocytosis, but which 

 differ from the normal opsonins in their greater thermostability; 

 these bodies have been designated as immune opsonins or bacterio- 

 tropins. Bodies of this character have been demonstrated following 

 immunization with the streptococcus, pneumococcus, staphylococcus, 

 meningococcus, the cholera vibrio, the typhoid and paratyphoid 

 bacillus, the dysentery bacillus, the tubercle bacillus, the plague 



