1 86 BACTERIOLOGY. 



they should be classed as Spirock&te. Metsch- 

 nikoff claims to have observed branched fila- 

 ments also, so that the comma bacillus may 

 perhaps belong in the cycle of development of 

 some species of Cladothrix, a group in which 

 all forms of comma bacilli have been actually 

 observed by Zopf (cf. Fig. 5). The germs are 

 decolorized by Gram's method. In the intes- 

 tine they occur not only free, but also in the 

 epithelium (Fig. 250), and can even penetrate 

 into the wall of the intestine itself as far as 

 the muscular layer. Further penetration, 

 however, ensues only in fatal cases, and then 

 only immediately before death ; the germs are 

 as a rule, however, found in the gall-bladder ; in 

 animal experiments, both when inoculated into 

 the peritoneal cavity or into the stomach, they 

 may occasionally pass over into the blood, in 

 which they sometimes appear like the Spiro- 

 ch&te of relapsing fever (Fig. 26 A). The ef- 

 fect produced in man depends less upon their 

 proliferation in the intestine and in the intes- 

 tinal epithelium than upon the formation of a 

 toxin which, with concomitant lowering of the 

 body temperature, proves fatal to men and sus- 

 ceptible animals. This proteid-like poison can 

 be formed not only analytically but syntheti- 

 cally also, as for example out of ammonium 

 lactate and asparagin. The toxin has been 



