228 BACTERIOLOGY. 



mode of growth under these circumstances must always 

 be borne in mind, otherwise much labor will be ex- 

 pended in vain. In tissues the typhoid bacilli do not 

 lie ssattered about in the same way as do the organisms 

 in tissues from cases of septicaemia. They are not 

 regularly distributed along the course of the capillaries ; 

 they are localized in small clumps through the tissues, 

 and it is for thes3 clumps, which are easily detected 

 under the low-power objective, that one should search. 

 When the section is prepared for examination, if it is 

 gone over with the low-power ol)jective, one will notice 

 here and there little masses that look in every respect 

 like particles of staining-matter which have been pre- 

 cipitated upon the section at that point. If these little 

 masses are examined with a higher power objective, 

 they will be found to consist of small ovals or short 

 rods so closely packed together that the individuals 

 composing the clump can be seen only at the very 

 periphery of the mass. This is the characteristic ap- 

 pearance of the typhoid organism in tissues. The 

 little masses are usually in the neighborhood of a 

 capillary. 



Result of Inoculation into Lower Animals. — 

 A great many experiments have been made with the 

 view of reproducing the pathological conditions of this 

 disease, as seen in man, in the tissues of lower animals, 

 but with limited success. Fatal results without the 

 appearance of the typical pathological changes have fre- 

 quently followed these attempts, but in most cases they 

 could be easily traced to the toxic,^ rather than to the 



' Toxic — poisonous results not necessarily accompanied by the 

 growtli of organisms in the tissues. 



