Monthly Microscopical l 
Journal, Dec. 1, 1869. J 
in Organic Infusions. 
311 
ing on the hypothesis of " spontaneous generation," or heterogeny^ 
and state more fully what I believe to be the true explanation of 
them. When treating of the fungus of the cork infusion, I stated 
that the cell, from the contents of which the fungus spread, appa- 
rently remained intact. In the case of the pollen exactly the same 
thing is shown. Whatever organic development takes place, the 
material of the pollen-cell, or shell, itself remains in the same state, 
so far as can be ascertained. This agrees with what takes place 
when leaf-tissue is experimented with, the microzymse from it being 
quite independent of the material of the cells themselves, which 
float about in the fluid after loss of their contents. This fact 
appears to me to prove conclusively, what all my experiments have 
tended to estabhsh, that the organic evolution of which I have 
given details is not due to any process of decomposition of the 
organized substance. If so, however, it cannot be the result of 
" spontaneous generation." One of the fundamental requirements 
of heterogeny is the existence of a putrescent body in contact with 
air and water. Without decomposition there can be no spontaneous 
generation or organization, but when this is given the organic pro- 
ducts are supposed to show themselves spontaneously — that is, 
without derivation from a pre-existing germ, even in the substance 
itself, which may, M. Pouchet declares, be reduced to charcoal, 
before it is infused, to ensure the destruction of all organic life. 
To me, however, such a notion as this is perfectly inexplicable. 
If the infused substance does not itself contain the germs of the 
future organisms, and if its organic character be thus absolutely 
destroyed, what remains to impress on the infusion afterwards made 
with it that peculiar character which gives rise to the phenomena of 
so-called " spontaneous generation ? " Nor is the experiment of boiling 
the infusion more satisfactory. For, surely, if boihng will not destroy 
that organic character of the fluid which is absolutely essential to its 
presenting the phenomena in question, this operation must be equally 
inocuous as against the organic germs that may be present in it, 
although invisible. In fact, the admitted phenomena of heterogeny 
disprove, so far as I can judge, the entire hypothesis. M. Pouchet 
says that the granulated jpdlieule jproligere — " la plus elementaire 
qu'il soit possible d'observer" — "est evidemment form^e par des 
cadavres de Monades ou de Bacteriums ; " * and on the preceding page 
he says that this pellicule " est constamment formee, des son en- 
gine, par d'infimes microzoaires." But whence come the first 
microzoaires ? The heterogenist says that they appear spon- 
taneously. But from what? Not from the fluid simply, since 
without the presence of the decomposing, or rather infused, sub- 
stance, the phenomena would not show themselves. Not from the 
substance itself, adds the heterogenist, because " a I'etat de dissolu- 
* * Heterogenie,' p. 355. 
