298 TYPHOID FEVER. 



indicated that this bacillus (known as Emmerich's bacillus 

 or the bacillus Neapolitanus) was identical with that 

 described by Escherich. Weisser, who worked at the 

 subject, pointed out that the B. coli was a normal in- 

 habitant of the human intestine ; and, further, comparing the 

 growth characters of the bacillus coli communis with those 

 of the typhoid bacillus, noted the similarities which exist 

 between the two microbes. 



From this time forward, the question of the morpho- 

 logical relationships of the two organisms has played an 

 important part in the bacteriological investigation of the 

 subject. There has been much controversy as to whether 

 they are varieties of the same species, and also as to 

 whether, in view of the fact that the B. coli is a normal 

 inhabitant of the human intestine, the B. typhosus may not 

 originate de novo from it in every case. The result is a 

 growing conviction that, for an unknown time, at any rate, 

 the two have been distinct species. Within late years the 

 significance of the pathogenic effects which the B. typhosus 

 produces in animals has been much discussed, and the 

 production by it of toxic bodies has formed the subject of 

 many investigations. 



The Bacillus Typhosus Microscopic Appearances. 

 Most observers will agree with Gaffky in attributing any 

 failure to find typhoid bacilli in the organs of a typhoid 

 patient to the difficulties of the search. Numerous sections 

 of different parts of a spleen, for example, may be examined 

 before a characteristic group is found. The best tissues for 

 examination are a Peyer's patch where ulceration has not 

 yet commenced or where it is just commencing, the spleen, 

 the liver, or a mesenteric gland. The spleen and liver are 

 better than the other tissues named, as in the latter the 

 presence of the B. coli is more frequent. From scrapings 

 of such solid organs dried films may be prepared and 

 stained for a few minutes in the cold by any of the strong 

 staining solutions, e.g., with carbol-thionin-blue, or with 

 Ziehl-Neelsen's carbol-fuchsin diluted with five parts of 

 distilled water. As a rule, decolorising is not necessary. 



