MECHANISM OF PROTEIN HYDROLYSIS AND IMMUNIZATION 55 



elusive. "Carrel and Ingebrister have produced hemolysins in 

 the growing embryonic spleen." As to agglutinins, it is noted 

 that "there is some evidence of agglutinin formation in the spleen 

 offered by V. Emden, Jatta, and Girgoleff." 



All this is interesting; but there are contradictory experiments 

 all along the line, and Gay and Rusk do not regard the evi- 

 dence on the whole as conclusive. They say, however, "there 

 seems greatest agreement on the point that antibodies are formed 

 either by the leucocytes or the leucocyte- forming organs. And 

 yet a good deal of recent work points with increasing emphasis 

 to the liver, an organ which, in view of its other functions, might 

 logically likewise serve to produce antibodies. 



It will appear that the conflicting testimony is largely har- 

 monized so soon as we take account of the red corpuscles along 

 with the leucocytes and cytogenic system. For the moment, how- 

 ever, it suffices to point out that all the different experimenters 

 are at one in designating either (1) the leucocyte- forming organs, 

 or (2) the leucocytes themselves, or (3) the liver, as the prob- 

 able sources of the origin of antibodies. As to the liver, I now 

 call attention to the fact that this organ is the seat of destruc- 

 tion of great numbers of red blood corpuscles ; and that its fluids 

 are very freely supplied with leucocytes, some of which come to 

 it directly through the portal vein after their apparent origin 

 in the spleen. It has even been suggested (by Sajous) that the 

 eosinophiles may be formed in the liver. 



All in all, it may fairly be said that the experimental evi- 

 dence raises at least a strong presumption in favor of the belief 

 that the lymphoid tissues that develop the leucocytes, and the leu- 

 cocytes themselves, are closely associated * with the processes 

 through which certain types of antibodies are developed. The 

 antibodies in question, according to the Proteomorphic theory, 

 are the "complement" and sundry bactericides, bacteriolysins, 

 agglutinins, opsonins, and precipitins in a word, the antibodies 

 evoked by antigens composed of unbroken proteins, including, 

 of course, the bodies of living and dead bacteria. 



If the direct evidence for this part of the theory is not abso- 

 lutely demonstrative, at least it may be said that there are no 

 experiments that clearly contradict it. Meantime, it is worth 

 while to inquire whether the general relations of the leucocyte 

 and its parent cells, viewed in the evolutionary scale, are such 

 as to justify the assumption that they perform the particular 

 functions here ascribed to them. Such a discussion could, of 

 course, have no force were it contradicted by direct experimental 

 evidence; but it may have confirmatory value when its findings 

 seem to accord with those of the experimenters. 



