AaaLUTINIXS A\D A<;f!IA:ri\.\Tl(>\ 183 



tissues, part may be destroyed, since only traces appear in the urine. 

 It resists autolysis. ^^ 



AGGLUTININS AND AGGLUTINATION ''^ 



This wi'll-kiiown plienonienon. the clumping or agglutination of 

 bacteria when acted upon by the serum of immunized or infected 

 animals, can hardly be considered as a means of defense, since we 

 have no evidence that it in any way protects the aniraal.^*^ Agglu- 

 tinated bacteria seem not to be severely injured by the process, 

 and can grow vigorously in agglutinative serum. Possibly agglutina- 

 tion favors phagocytosis and lessens dissemination of the infecting 

 organisms, but it is improbable that the influence on the course of 

 infection is great. Agglutination, therefore, may be looked upon as 

 an incident in the infection, rather than as a definite method of re- 

 sistance, and it is equally well produced hj immunizing with foreign 

 cells or any foreign protein masses of suitable size which contain 

 soluble antigens. 



For the production of agglutination it is necessary that the cell 

 contain an antigen {agglutinogen) which has an ai^nity for the specific 

 constituent of the serum, agglutinin. Normal serum may contain 

 agglutinin ; e. g., typhoid bacilli are sometimes agglutinated by normal 

 serum, even when it is diluted thirty times, but by immunization this 

 property can be greatly increased until agglutination may be obtained 

 with dilutions as high as one to a million. Whether normal agglutinins 

 are essentially different from immune agglutinins is not known.^® 

 Many protein solutions, especially extracts of plant tissues and legum- 

 inous seeds, cause marked non-specific hemagglutination. "'' Likewise, 

 bacterial extracts may agglutinate red corpuscles.''^ In immunization 

 the agglutinogen, which is probably an intracellular protein, acts as a 

 stimulator to the formation of the specific agglutinin. Hence, when we 

 inject either extracts of cells or entire cells, we secure agglutinins, 

 for the agglutinogens are liberated from the cells upon their disinte- 

 gration. In erythrocytes the agglutinogen seems to be in the stroma.®^ 



We can obtain agglutinins against nearly all bacteria, including 

 non-pathogenic forms, but in varying strengths. Agglutinins are 

 found in the blood stream in the highest concentrations, but they are 



— 57 Wolff-Eisner and Eosenbaum. Boii. klin. Wndi.. lOOfi (43), 94.5. 



58 Bibliocrraphy piven by Miiller, Oppenheimer's Handbuch der Bioohemie. 1900 

 (II (1) ). .592: Landsteiner, ihid., p. 428: Paltanf, Kolle and Wasserniann's Hand- 

 buch., 1913 (II), 483. 



58a Bull, however, would ascribe much importance to aff^lutination of bacteria 

 for their removal from the circulation (.Tour. Exp. Med., 191,5 (22), 484). 



59 See Andrejew, Arb. kaiserl. Gesundhtsamt., 1910 (33), 84. 



60 Mendel, Arch. Fisiol., 1909 (7), 168. 



Gi Fukuhara. Zeit. Immunitat., 1909 (2), 313. 

 •■'^ Chyosa, Arch. f. Hyg., 1910 (72), 191 



