TYPHOID FEVER. 403 



the evidence in favor of the various organisms 

 which have been supposed by different observers 

 to be the veritable typhoid germs, is mainly that 

 obtained by the microscopical examination of the 

 tissues involved in the local lesions which character- 

 ize the disease. When we consider that the healthy 

 intestine is the usual habitat of a large number of 

 species of bacterial organisms, and that some of 

 these promptly invade necrotic tissues, and pos- 

 sibly living tissues having a low grade of vitality, 

 or which are deprived of their normal relations by 

 inflammatory exudates which furnish a suitable 

 pabulum for parasitic micro-organisms, we shall 

 appreciate the difficulty of deciding whether necro- 

 sis of invaded tissues is a result of the parasitic 

 invasion, or whether the mycosis has been secondary 

 to and independent of the morbid process. 



Eberth seems to have very fully appreciated 

 these difficulties, and it is doubtful whether any 

 more satisfactory evidence can be obtained than 

 that which he has offered in favor of the view that 

 the bacillus described by him is the much sought 

 typhoid germ, unless future experiments upon 

 the lower animals give more definite results than 

 have been heretofore reported. As pointed out by 

 Eberth, the results reported by Walder in his experi- 

 ments upon calves, dogs, cats, rabbits, and chickens, 

 are entirely unreliable, as no account seems to 

 have been made of septicsemic complications which 

 could scarcely fail to occur from the ingestion of 

 putrid material, blood, typhoid stools, etc., used 



