INFECTION AND RESISTANCE 



ent in the new-born animal, but are acquired later in life, possibly 

 because of the absorption of bacterial products from the intestinal 

 canal. It has been variously shown, 46 too, that living bacteria them- 

 selves may enter the lymphatics and the portal circulation from the 

 intestine during apparently perfect health of the individual. 



This subject is of interest, not only in connection with the ag- 

 glutinins, but has bearing upon the existence of normal antibodies 

 in general. Ruffer, 47 who has studied particularly the penetration 

 of leukocytes and bacteria through the intestinal mucosa, demon- 

 strated micro-organisms in the sub-mucous lymph nodes of normal 

 rabbits, and Ribbert 48 and Bizzozero 49 have shown the presence of 

 bacteria in apparently normal mesenteric lymph nodes. Adami 

 and Nichols even claim that during health a certain number of liv- 

 ing bacteria enter the portal circulation from the intestine, and from 

 here may get into the systemic circulation, and are ordinarily de- 

 stroyed by either leukocytes, liver lymphatic organs, or the kidneys. 



It is thus not surprising that normal agglutinins should occur, 

 and that they should be qualitatively identical with the so-called 

 "immune" agglutinins, since they probably arise by a sort of spon- 

 taneous immunization through the intestinal canal. From the in- 

 vestigations of Ford especially we may conclude that the immune 

 agglutinin may be regarded as merely a quantitative increase of the 

 normal antibody, if this has been present before immunization. 

 Ford 50 found that when an animal is treated with an agglutinating 

 serum an anti-agglutinin may be obtained which neutralizes the 

 action, not only of immune, but also of homologous, normal ag- 

 glutinin. 



An interpretation of the process of agglutination, according to 

 the theory of Ehrlich, conceives it as a chemical union of agglutinin 

 and bacteria (agglutinogen). The agglutinin is regarded as con- 

 sisting of two atom complexes, one the "haptophore," having af- 

 finity for the bacterial protein, and concerned with the union, the 

 other the "ergophore" or "zymophore," by means of which the actual 

 agglutination is brought about after the union has taken place. Un- j 

 like the antibody concerned in the processes of hemolysis or bac- ! 

 teriolysis, the agglutinins are not dependent in their action upon the , 

 cooperation of alexin, and the agglutination power of a serum is 

 therefore not destroyed by inactivation or heating to 56 C., as is 

 the case with the former. Although the accurate point of thermal 

 destruction varies with different agglutinins (the agglutinins for the 

 Bacillus peslis and a few other bacilli are said to be destroyed at 



46 Adami. Jour. Am. Med. Assoc., Dec., 1899. 



47 Ruffer. Brit. Med. Journal, 2, 1890. 



48 Ribbert. Deutsche med. Woch., 1885. 



49 Bizzozero. Centralbl. f. d. Med. Wiss., Vol. 23, 1885, p. 49. Quoted 

 from Adami. 



50 Ford. Zeitschr. f. Hyg., Vol. 40, 1902. 



