INFECTIONS OF THE DIGESTIVE TRACT 169 



course like that of typhoid fever, but as a rule milder 

 this milder course corresponding to the intermediate 

 position of the bacilli between colon bacilli and typhoid 

 bacilli. The justification for separating the paratyphoid 

 bacilli from those of typhoid has been questioned by 

 some, but the biochemical distinctions between them 

 are definite, and as the recognition of these distinctions 

 is serviceable to man, it is desirable to emphasize them. 1 

 With the recognition of these different etiological factors 

 the unity of the condition we call typhoid fever is swept 

 away. This unity is in fact still further broken by the 

 fact that another bacillus of the colon group, B. facalis 

 alcaligenes, has lately been shown to be the inciter of 

 febrile states clinically inseparable from mild forms of 

 the fever caused by the typhoid bacilli. 



It is an inevitable event in the development of bacterio- 

 logical science that different investigators should some- 

 times discover the same microorganism in its relation 

 to different diseases and that under these conditions 

 of discovery the organisms in question should come to 

 bear different names. Thus it has lately been insisted 

 that the bacillus of paratyphoid B is identical with the 

 bacillus of mouse typhoid and with the well-known 

 B. enteritidis 2 of Gartner. In this case the identity 



1 So long as the possibility remains that closer study may re- 

 veal some differences of a characteristic sort between the lesions 

 and pathogenesis of the disease caused by typhoid bacilli and the 

 disease caused by paratyphoid bacilli it is perhaps permissible to 

 speak of the latter class of cases as paratyphoid fever. 



2 Kutscher u. Meinicke, " Vergleichende Untersuchungen iiber 

 Paratyphus-, Enteritis-, und Mausetyphusbakterien und ihre im- 

 munisatorischen Beziehungen," Zeitschr. /. Hyg., Hi, p. 301, 1906. 



