XI] BACILLI : SPECIFICALLY PATHOGENIC 237 



— whenever such an examination is made by microscopic 

 or cultural specimens — this bacillus occurs in numbers. In 

 the intestinal contents and in the typhoid stools the true 

 typhoid bacillus can be also identified, although this 

 examination is only in comparatively few cases successful, 

 on account of the great number of bacillus coli present, and 

 it is for the same reason that if the typhoid bacillus is so 



Fig. 



-Impression Specimen of a vekv -^-oi-ng Colony of the T^thoid 

 Uacillus ox (Ielatine. 



demonstrable it is in cases in which the Peyer's glands 

 have already begun to ulcerate, i.e. in the second and third 

 week of the disease, that is when their number passed from the 

 tissue of the mucous membrane is sufficiently great. In the 

 blood of the general circulation in typhoid fever the bacillus 

 is not demonstrable, except in very rare instances, and 

 then only after the second week. From this the conclusion 



