Monthly Microscopical "I 
Journal, Dec. 1, 1869. J 
in Organic Infusions. 
307 
of this kind I have described elsewhere in the following words : — 
" On examining a drop of diluted cream under the microscope, we 
find that its globules are of various sizes, and that the smaller ones 
have an extremely active movement. Moreover, if a small quantity 
of cream be placed in water, after a few hours these smaller glo- 
bules are found to have become both more active and more nume- 
rous. In the course of some days a further change takes place, 
many of them having taken an elongated form, and finally the 
cream infusion is full of animal life of a very active character." It 
is at a later stage that the vegetation makes its appearance in a 
form exactly resembling, as I have already said, the fungus de- 
veloped in an infusion of cork. There is the same formation of 
cells, and the apparent budding out " from them of masses of 
matter resembling jelly. In another infusion these curious-looking 
bodies were apparently produced by elongation of the globules them- 
selves, and they then amalgamated to form the fungoid stem. All 
the globules in this infusion, moreover, sprouted," and thus gave 
rise to a fungoid growth. In the cream infusion also there is pro- 
duced a kind of fruit on the fangus — spherical bodies resembling 
the original " oil-globules " — and infusorial forms similar to those 
met with in the cork infusion are finally produced. This fungus 
appears to be a species of Ascophora. 
These are the phenomena to be accounted for, and to simplify 
the matter I shall first of all state the conclusion I have arrived at 
as to the true explanation of them, and afterwards support this 
conclusion by other facts which have come under my own observa- 
tion. The data are, simply, that, in the one case, from a vegetable 
substance — cork — and, in the other, from an animal substance — 
milk — both vegetable and animal organisms have been derived in 
such a manner as that we must suppose the higher to have sprung 
from the lower organism. We are, in fact, in the presence of the 
phenomena now explained by an increasing number of men of 
science as the result of " spontaneous generation," as it is popularly 
called, or by virtue of what is scientifically termed heterogeny. I 
shall have a few remarks to make on this hypothesis shortly, and 
I wiU say here only that, as usually understood, this hypothesis will 
not explain the phenomena in question. Decomposition is abso- 
lutely essential to " spontaneous generation," while here, so far 
from there being decomposition, every step in the process is an 
evolution of vitality. If we take the infusion of cork, we find that 
the fine filaments first developed can be traced distinctly to the cork 
cells, and yet these cells remain, apparently, intact, and they may be 
seen in the infusion undecomposed to the end of the experiment. 
The development is evidently from the cell-contents, whatever these 
may be. Moreover, all the further changes which take place pre- 
sent themselves simply in the course of this development. The 
