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 (Bacteriwm, Bacillus), zooglairian 
(colonies, or zoogloea), submerged hyphe (torula, 
chaplets, or chains), fructiferous filaments (endogenous 
spores), the whole constituting the algous phase of the 
eryptogam 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 aérial mycelium on 
which the aérial 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 
