134 PHYSIOLOGY OF THE BACTERIA. 
sults of such culture experiments are far from 
being so certain.. Not having succeeded in re- 
moving them completely from the invasion of for- 
eign germs, the greater number have seen the 
most diverse forms develop themselves, and from 
this have inferred the most remarkable transfor- 
mations. 
Thus, Hallier pretends to have observed the 
transformation of Micrococcus into various fungi, 
such as Mucors, Ustilago, etc. The M. of vaccinia 
comes from Torula rufescens, which is itself a 
phase of development of Ustilago carbo; the M. 
of human variola is derived from a fungus having 
sporangia and pycnidia, related to Stemphylium 
sporidesmium ; that of the variola of animals 
from Cladosporium (Pleospora) herbarum ; the 
M. of the blood of scarlatina belongs to the 
g. Tilletia; those of glanders and of syphilis 
from a Coniothecium, etc. In the same way Letz- 
erich has referred the M. of diphtheria to another 
Tilletia, the 7. diphtherica. 
The transformation of bacteria into “ leviires” 
(yeast fungi), and these into Penicillium, has been 
admitted by Hallier, Trécul, and others. But the 
researches of Brefeld and de Seynes have shown 
us that this is far from being demonstrated ; in- 
deed, in his numerous cultivations, de Seynes has 
never been able to verify such an affiliation; and 
Nageli in his turn has never been able to obtain 
a transformation of schizomycetes into budding 
fungi. 
It is the same as regards the transformation of 
