14 



granted the interaotiou between the micro-organism and tlie leucocyte, wo 

 may legitimately admit tliiit there is destruction.* In addition, therefore, 

 to exciting the chomiotactic properties of the white corpuscles, the 

 "toxines" of pathogenic bacteria may produce a proliferation of the 

 leucocytes in the lymphatic glands. Apart from the old world proof of 

 this proliferation, there is the more recent proof supplied by Buchner f 

 and Tchistovitch.l Thus here is provided an additional argument ia 

 favour of regarding the leucocytes as important factors in the prevention 

 of disease. 



But when we come to examine more nearly into the facts for and 

 against the possession of bactericidal powers by the body fluids within 

 the organisms, we find that there is so far a want of conclusive evidence 

 in favour of assuming that it exists. The statements of Emmerich and 

 di ]\Iattei, of Nissen, and others, that bacteria injected into the circula- 

 tion are destroyed more rapidly than could be accounted for by phagocy- 

 tosis, have, as I have shown, been shaken by Metchnikoff. Lubarsch, a 

 very careful observer, states certainly that the spores of anthrax are 

 inhibited from developing in the frog, whether they be enclosed within 

 cells or free in the lymph ; and more recently Sanarelli§ has, by placing 

 anthrax bacilli in small closed tubes formed of collodion, and filled with 

 lymph which had diffused through the walls when the tubes were placed 

 in the subcutaneous lymph sac of frogs, shown that these undergo 

 r,lteration in consequence of the action upon them of the lymph, free 

 from cellular elements. If this be correct, it only shows that the 

 body fluids have a destructive action much feebler than that possessed 

 by the leucocytes. 



In this connection may be mentioned Bouchard's observations upon 

 the bacillus pyocyaneus aud his theory advanced at the Berlin Congress 

 that immunity is primarily due to the condition of the humours. 

 Pathogenic bacteria, according to him, give rise to substances which 

 hinder the inflammatory process, and it is only when these substances 

 are inadequately represented, or when yet other bacterial products 

 have stimulated the cells, that the cells intervene. The organism 

 rendered refractory becomes an unfavourable soil for the production of 

 these inhibitory bodies, and in consequence of this altered conditina of 

 the humours inflammation occurs, fi'ee emigration of the leucocytes takes 

 place, aud phagocytosis ensues. But this theory unfortunately does not 

 embrace all cases. Many very virulent diseases cause well-marked in- 

 flammatory changes, and it may be laid down that in a large number of 

 acute diseases, what we have to deal with is not an absence but a modi- 



* See also Caiiparelli.—6V)i()'a(6!a(J/. BakUriologie, Vol. X., ISOl, p. i~'. 



tBuohner.— J/iincAcHfi- taal. U'oclunsdn; ISOO, No. 47. 



t Tchistovltch. — Annaks de I'lnstitut Pasteur. July, 1891. 



§ Sanarelli.— CcnJmtttaU/. Baktcriologie, Vol. IX., 1S91, Nos. 14-16. 



