264 Chapter IX 



fluids, such as the pericardial fluid, oedemas very poor in formed 

 elements, etc.) it follows that the agglutinin circulates in the 

 blood and lymph of the living animal. Several observers, amongst 

 whom I may cite Achard and Bensaude^ Arloing^, and Widal and 

 Sicard^, put to themselves the question whether, before passing 

 into the blood, the agglutinin is not formed in the exudation de- 

 veloped at the seat of inoculation of the micro-organisms. Their 

 conclusions w^ere invariably negative; they were never able to find 

 more agglutinins in these exudations than in the blood. Pfeiffer 

 and Marx* had occasionally observed that their animals, inoculated 

 with the cholera vibrio, early exhibited an agglutinative powder in 

 the spleen; but tliis result was not met with sufficiently constantly 

 to enable them to draw a positive conclusion. A little later, van 

 Emden^ studied in detail the distribution of the agglutinative pro- 

 perty in the body of an animal inoculated with Bacillus aerogenes. 

 His researches led him to the conclusion that the spleen and the 

 lymphoid organs must be regarded as the source of the agglutinins. 

 [278] Shortly after the inoculation of the bacilli, an extract of the spleen 

 was more agglutinative than the blood or any of the other organs. 

 In rabbits from which the spleen had been removed, the same role 

 was filled by the bone marrow and probably also by the lymphatic 

 nodules. But this preponderance of the haematopoietic organs did 

 not continue long, the blood soon becoming the most important 

 seat of the agglutinative power. 



The proof that this question of the origin of the agglutinins is 

 a very delicate and difficult one is afforded by an investigation very 

 carefully carried out by Gengou^ on the agglutination of the 

 attenuated anthrax bacillus (Pasteur's first vaccine) by the fluids and 

 organs of normal and prepared guinea-pigs. This observer was never 

 able to obtain any confirmation of the results obtained by van Emden 

 with another micro-organism. In Gengou's guinea-pigs it w^as always 

 the blood fluid which showed itself most agglutinative, the organs 

 exhibiting merely a feeble and inconstant agglutinative power. As the 



^ Arch, de med. exper. et d'anat. path., Paris, 1896, l'"^ serie, t. viii, p. 759. — 

 Bensaude, "Le phenomene de I'aggluti nation des microbes," Paris, 1897, p. 252. 



2 Compt rend. Soc. de biol., Paris, 1897, p. 104. 



3 Ann. de VInst. Pasteur^ Paris, 1897, t. xi, p. 376. 



4 Ztschr.f.Hyg., Leipzig, 1898, Bd. xxvii, S. 272, 

 s Ztschr.f. Hyg., Leipzig, 1899, Bd. xxx, S. 19. 



^ Arch, internal, de Pharmacodyn., Gand et Paris, 1899, vol. vi, p. 299. 



