LIFE-HISTORY OF PENICILLIUM. 345 
cillium. Trécul, in 1868 and 1869, tried to show that Peni- 
cillium, Mycoderma, and Torula were different forms of the 
same species, and in 1871 he attempted to trace back the 
formation of Penicillium. According to his views, albu- 
minous materials change into Bacteria, or directly into yeast 
and Mycoderma, or the Bacteria change into the lactic acid 
ferment; this develops into yeast, then into Mycoderma, 
which lastly becomes Penicillium. 
In 1865 Hoffmann invented his apparatus for cultivating 
these fungi, and this directed observations into a new channel. 
According to Hoffmann, yeast was a typical unicellular fungus 
—a special vegetative form of the mycelium of Penicillium 
glaucum, or more rarely of Mucor racemosus, sometimes of 
both, or even of other moulds, the access of atmospheric air 
being necessary to cause the fructification of the yeast to 
assume the form of Penicillium. Bail closely follows Hoff- 
mann, and obtains Penicillium and Mucor from yeast.! 
Under water the spores of Penicillium and Mucor produce 
Torula; on the surface of fluid mycelium and conidiiferous 
hyphe are formed. Bail also states that if flies eat yeast they 
become affected with Empusa if their bodies are under water, 
with Achlya if the body is on the surface, while the portion 
of the fly above the water produces Mucor. 
Hallier stated that when Penicillium grows on a definite 
nutrient substratum it produces Penicillium only, and if 
other forms of fruit are developed it 1s on account of a change 
in the conditions. ‘Thus, on moist bread Mucor develops 
from Penicillium ; on milk, Leptothrix ; and from Leptothrix, 
Torula. The development shows that the genera Penicillium 
and Mucor must be united, and that five other genera must 
be suppressed, viz. Achorion, Leptothrix, Hormiscium, 
Cryptococcus, and Trichophyton. By different nutritive 
materials eight different things can be got from Penicillium. 
If the spores of Penicillium are placed in water they rupture, 
and the granular contents escape in the form of small moving 
particles (Micrococcus, Bacterium), which come to rest after 
repeated division and form a single-jointed thread. In 1868 
and 1869 Bail and Hoffmann published other papers on the 
relations of yeast and mould. 
In 1870 Reess examined yeast, and declared it to be a 
' Professor Huxley, however, has found that when swbmerged in a sac- 
charine liquid “ the mode of development of the younger hyphx becomes 
changed. They break up, by a process of constriction, into short lengths, 
which separate, acquire rounded forms, and at the same time multiply after 
the manner of Zorule. Coincidently with these changes, an active fer- 
mentation is excited in the fluid, so that this ‘ Mucor-Torula’ functionally, 
as well as morphologically, deserves the name of yeast.”—Lbs. 
