M. H. Hoffmann on Fermentation. 275 
tube in as oblique a position as possible. The spores, which 
contain air, and are therefore specifically very light, rose as 
usual; but instead of meeting the air, they came in contact with 
the wall of the tube, and often remained immersed in the fluid. 
The tube was agitated once a day; and as early as the second or 
third day a mycelium was developed around the spores, and at 
this point, and then only, an evolution of gas commenced, From 
this time the tube had to be shaken more frequently.- This ex- 
periment, modified in many different ways, proves that the de- 
velopment of the gas is intimately connected with the vegetation 
of the Fungus. In course of time the liquid becomes acid, and 
the evolution of gas ceases. If it be examined by the microscope, 
besides a few fructiferous filaments (in their atypie state), it is 
found to consist of mycetoid filaments and spores in various 
stages of germination, besides a great many yeast-cells in all 
phases of development.. 
A fermentation of greater or less strength may be produced 
not only with the spores of Penicillium, but also with those of 
other Fungi. M. Hoffmann succeeded in setting up fermenta- 
tion in fresh wort, in grape-sugar, cane-sugar, and boiled goose- 
berry juice, by adding to the fluids spores of Ustilago carbo, 
Ascophora mucedo, and Stachylidium pulehrum, and also by 
putting in rose-leaves infected by Phragmidium incrassatum, and 
Uredo Rose, and finally by means of Torula fructigena, Pers, 
The dust collected on books also produces fermentation, The 
liquid at first contains yeast and a greater or less number of 
Bacteria ; finally, Peniciliia or Ascophore are developed on its 
surface, 
The yeast thus artificially produced has all the physical and 
chemical properties of the ordinary yeast of the juice of raw 
fruits, M. Hoffmann has even made leayen with yeast produced 
by means of the Fungi of the Rose, On the other hand, he 
never succeeded in producing fermentation or the formation of 
yeast by means of fresh spores of Agarics or Boleti. From this 
it follows that all Fungi cannot assist in the production of yeast, 
This property appears to depend upon their capacity of forming 
conidia by their filaments of germination, and also perhaps upon 
the fact of their having been produced upon parts of plants in 
good health, or dead or dying. M. Hoffmann is inclined to think 
that this property of decomposing and penetrating deeply into 
the surrounding fluids is due especially to the mycetoid fila- 
ments. 
And now the question presents itself, what part do Fungi and 
Infusoria take in the decomposition and putrefaction of organized 
bodies ? 
If certain Fungi (and Infusoria) alone possess the property of 
