194 MICROBES, FERMENTS, AND MOULDS. 



Many other bacteria appear in the intestines when 

 the disease is approaching its end, but the bacillus in 

 question is the only one found in the blood and 

 internal organs, so that it is really characteristic of 

 the disease. 



Gaffky, a German micrographist, and a pupil of 

 Koch, has succeeded in the artificial culture of this 

 microbe, taking it from the spleen of persons who died 

 of typhoid fever. It is actively developed on gelatine 

 and potatoes, becomes very lively and produces endo- 



Fig. 86. Bacilli of typhoid fever (x 1500 diam.): three red corpuscles may be 

 observed in the same preparation. 



genous spores at a temperature of 38. But the inocu- 

 lation of animals with the disease has hitherto been 

 unsuccessful, at least so as to reproduce in them an 

 affection of the intestines, really resembling that of 

 Peyer's glands in man. 



The horse is the only animal affected by a similar 

 disease, which has also been called typhoid fever. In 

 1881, the horses of the Paris Omnibus Company were 

 decimated by an epidemic of this nature. But the 

 lesion of Peyer's glands cannot be compared with that 

 which occurs in the same glands in man, and no 

 special microbe has yet been discovered. 



