336 BACTERIA IN INFECTIOUS DISEASES. 



growths, especially the tubercles, under the skin 

 of these animals. He says, " I was not lucky in 

 any of these attempts." (1880.) More recently 

 he has inoculated a monkey, which, at the date 

 of his report, had been under observation for six 

 months, without having developed any symptoms 

 of the disease. But as the time of incubation in 

 man is said to be a year or more, this experiment 

 is not considered decisive. 



The bacilli have been successfully cultivated by 

 their discoverer upon gelatinized blood-serum. In 

 these cultures development commenced after an 

 interval of three or four days, and the bacilli 

 often presented nodular enlargements at the ex- 

 tremities, which were believed to be due to the 

 formation of spores. In these cultures filaments 

 formed, made up of a number of bacilli, and these 

 were often so abundant as to form an entangled 

 net-work. The fact that these bacilli multiply and 

 develop spores in a culture-solution, within a few 

 days, while the period of incubation in leprosy is 

 "at least a year," seems a little difficult to recon- 

 cile with the supposed etiological role of these 

 parasites. 



MALIGNANT (EDEMA. According to Koch, a 

 frequent source of error in experiments on anthrax 

 arises from accidental contamination of the culture- 

 fluids by a bacillus which closely resembles B. an- 

 thracix. This organism is called the bsx'illns of 

 malignant oedema, and the disease to which it gives 



