THE MICROBES OF HUMAN DISEASES. 203 



FeiTan regards this peronospora as the infectious 

 agent of cholera. Yet it seems extraordinary that 

 such a remarkable polymorphism should have escaped 

 the observation of Koch and of the numerous micro- 



Figs. 88, 89, 90.— Evolution of cholera microbe {Pernnospora Ferrani : Feiran') ; 

 1. ClioleTa microbe {Jiadllus komma\ discovered by Kocti. '2. Spiral form of 

 bacillus, transferred from gelatine to an infusion. 3. Degeneration of spiral 

 form after a series of successive cultures. 4. Cholera microbe {Peronospora 

 Ferrani): development of oogonium on the spirilla and straight filaments. 

 6. The oogonium is filled with granules which centre in a point &, and it is then 

 converted into an oosphere ; m, poUinidium on fertilizing oi gan. 6. The oosphere 

 is converted into mull>erry-sbaped and comma-shaped tjodies. 



graphists who have made various cultures of the 

 comma bacillus. It is difficult not to suppose that 

 some negligence or error has vitiated Ferran's re- 



