BACILLUS TYPHOSUS. 413 



are not of necessity distributed along the course of the 

 capillaries, but are localized in small clumps through 

 the organs, and it is for these clumps, which are easily 

 detected under a low-power objective, that one should 

 search. This peculiar clumping of the typhoid bacilli 

 in the tissues cannot be satisfactorily explained. It 

 may possibly be due to the specific clumping or agglu- 

 tinating influence that typhoid blood has been shown to 

 have upon the typhoid bacillus, a phenomenon that is 

 readily demonstrable in the test-tube or under the 

 microscope. In other words, may it not be simply the 

 result of an intracapillary "Widal reaction"? (See 

 Widal Reaction.) 



When the section is prepared for examination, if it 

 be gone over with a low-power objective, one will 

 notice at irregular 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 masses are examined with a higher power 

 objective they will be found to consist of small ovals or 

 short rods so closely packed that the individuals com- 

 posing the clump can often be seen only at the extreme 

 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. 



Eesult of Inoculation into Lower Animals. — 

 A great many experiments have been made in a variety 

 of ways with the view of reproducing the pathological 

 conditions of this disease, as seen in man, in the tis- 

 sues of lower animals, but with practically no success. 

 From the time of its discovery up to within a compara- 

 tively recent date there was an almost continuous con- 

 troversy concerning the infective properties of bacillus 



