POLYMORPHISM OF MICROBES. 275 



species, quite distinct in their action upon men and 

 animals. 



Polymorphism of Moulds. The comparatively 

 early researches of Hallier and others tend to show 

 that the fungi of moulds display considerable poly- 

 morphism, so as to completely overthrow the classi- 

 fication of these cryptogams. These researches have 

 been recently resumed by Cocardas, who considers 

 it proved that all the moulds found in saccharine 

 liquids which have been allowed to ferment and in 

 pharmaceutical extracts belong to one and the same 

 species, which is highly polymorphic, and which he 

 terms the Penicillium ferment. Cocardas asserts that 

 he has seen this Penicillium ferment pass through 

 the following successive stages : Corpuscular (Micro- 

 coccus), bacteridian (Bacterium, Bacillus), zooglairian 

 (colonies, or zoogloea), submerged hyphse (torula, 

 chaplets, or chains), fructiferous filaments (endogenous 

 spores), the whole constituting the algous phase of the 

 cryptogam which floats on the surface of syrup. 



The fungoid phase then begins. The swellings 

 formed on the surface of the liquid by the endogenous 

 spores bud ; these buds become elongated, partitioned, 

 and ramified, constituting the aerial mycelium on 

 which the aerial fructifications are developed, which 

 can only form outside the liquid. 



These fructifications, although all issuing from the 

 same mycelium, may present either the form of asper- 

 gillus, of mucor, or of penicillium, according to the 



