llEMAdCIJ TIMN 223 



those described for bacterial aygiutiiiatioji. Tlie hemagglutinating 

 antibody behaves like the other antibodies and proteins under the in- 

 fluence of chemical and physical agencies, but Landsteiner and Jagic 

 have obtained strong agglutinating solutions containing very little 

 protein. Bergel '^ contends that hemagglutination is produced by 

 lipase from the lymphocytes, which alters the lipoid membranes of 

 the erythrocytes. Agglutination occurs at much lower temperatures 

 than hemolysis, and also is not checked h\ heating the serum to 55° ; 

 hence it is possible to observe hemagglutination independent of hemo- 

 lysis. Serums may contain hemagglutinins and not "be hemolytic; 

 the reverse is also true. The conglutinin effect of beef serum (Bordet 

 and Gay) is also observed with corpuscles as with bacteria. As agglu- 

 tination occurs in corpuscles that have been fixed in formalin or sub- 

 linuite, it is probably not the proteins that are affected, but some other 

 of the ingredients of the stroma, of which lecithin and cholesterol seem 

 to be the chief. 



Certain vegetable poisons also produce agglutination of red cor- 

 puscles, especially ricin, abrin, and crotin, and the fact that ricin 

 has little or no hemolytic action shows the independence of the proc- 

 esses. Antisera for these vegetable poisons are also antiaggiutina- 

 tive, acting, as Ehrlich showed, on the poison and not on the corpus- 

 cles. The seeds of many non-poisonous leguminous plants, and also 

 of Solanacece, jdeld extracts that are strongly agglutinative for red 

 corpuscles; in Phaseolus multiflorus the active substance is found 

 in the proteose of the seed, and seems to be a part of the stored food 

 (Schneider).^* It is not present in other parts of the plant. Snake 

 venoms contain agglutinins, destroyed by heating to 75° ; their ag- 

 g-lutinating power being in inverse ratio to their hemolytic power. 

 Corpuscles agglutinated by venoms may be again separated by po- 

 tassium permanganate solutions.^^ Silicic acid and certain other 

 colloids may act as agglutinins, their effects bearing a relation to the 

 effects of electrical charges upon agglutination of bacteria or of col- 

 loids {q. v.).-'^ Corpuscles that have been sensitized by hemolytic am- 

 boceptors are much more readily agglutinated by salts of heavy metals, 

 especiall}'^ copper and zinc, presumably because of quantitative altera- 

 tions in the electrical charge of the corpuscles induced by the anti- 

 body.""'"^ 



Agglutination of the corpuscles during life va&y be of great patho- 

 logical importance, for such masses of agglutinated corpuscles may 

 readily produce capillary thrombi and emboli, which, if wide-spread, 

 may create much disturbance. Sometimes the serum of one indi- 

 vidual of a species agglutinates the corpuscles of another individual 



53Zeit. Immunitat., 1912 (14), 255; 1913 (17), 169. 



54 Jour. Biol. Chem., 1912 (11), 47; bibliographv. 



55 See Flexner, Univ. of Penn. Med. Bull., 1902 (1.5). .*324 and 301. 



56 See Landsteiner and Jagic, Miinoh. med. Woch.. 1904 (51), 1185. 

 56a Eisner and Friedemann, Zeit. Immunitiit., 1914 (21), 520. 



