316 BACTERIOLOGY. 



at a higher temperature (40 to 45 C.), then washed 

 out in absolute alcohol, and cleared up in xylol and 

 mounted in balsam, the bacilli (particularly if the tissue 

 be the liver or spleen) can readily be detected, massed 

 together in their characteristic clumps. If used in the 

 same way, the alkaline methylene-blue solution gives 

 also very satisfactory results. 



In searching for the typhoid bacilli in tissues, their 

 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 scattered about in the same way as do the organisms 

 in tissues from cases of septicaemia ; they are not regu- 

 larly distributed along the course of the capillaries, but 

 are localized in small clumps through the tissues, and it 

 is for these clumps, which are easily detected under the 

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

 section is prepared for examination, if it be gone over 

 with the low-power objective, one will notice at irregu- 

 lar intervals little masses that look in every respect like 

 particles of staining-matter which have been precipitated 

 upon the section at that point. When 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 often be seen only at the very periphery of 

 the mass. This is the characteristic appearance 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, 



