To?mS,K?ri86?] Spontaneous Oenerafion. 257 
great thing it has done for us, and that is this, it has opened up a 
vast field of research, and carried our knowledge into infinitesimal 
matter, in wliich it thins away until it seems to vanish into thin 
air, and yet as far as the eye can see does life reside. The minute 
cells of which both plants and animals are built up, the very petals 
of the flowers, and the eyes of the human subject, are swarming 
with hfe, not their own, but myriads of independent creatures, so 
that at last we are almost forced to accept the words of Bufibn, as 
referred to in the first part of this paper. 
Thales supposed all things to be generated out of water ; and in 
this he was not far wrong, as the beginning of life, so far as we are 
enabled to appreciate it, is mainly dependent on a certain state of 
humidity for its existence. Amongst the protophytes, or simplest 
plants, there are many of which every single cell is not only capable 
of living, but may be normally considered a distinct plant. For 
instance, observe the beginning of a lichen on a newly -hewn stone. 
It will there be seen to spring from a single cell, and this cell, 
should the condition of humidity continue favourable, will very 
soon develop others, so that in a short time a thin stratum of cells 
may be observed radiating in all directions. 
In the infusion of the liver of a fowl, and to which I shall again 
have to refer, I observed on my first investigation, eighteen hours 
after the infusion was made, a number of bluish elliptical cells, very 
much hke the spores or cells of a penicillium ; these had the power 
of propagating or continuing their like by a kind of gemmation, 
that is, the inner walls of the cells appear to develop minute gemms9, 
or little buds, which spring into cell-life ; and it frequently happens 
that one single cell may contain many generations of cells, as they 
are graduated down to extremely minute points, and at length lost 
to view. These cells propagate very rapidly, forming themselves 
into long moniliform masses. Now the difiiculty is how to account 
for these cells in this infusion, as I had done all that I could do 
to destroy life, by boiling the liver until it was all, or very nearly 
all, broken down or disintegrated, so that it appeared only as a 
molecular or flocculent mass. These cells measured about TY^T^th 
of an inch long. My impression is, that these cells were embedded 
in the flesh of the liver, as I do not believe them to have been 
admitted through the agency of the atmosphere into the vessel. 
Every provision was made to make the experiment as perfect as 
possible. 
Dr. John Lowe * mentions the case of peculiar cells being found 
in the lungs and kidneys of a man. These cells measured yo^oij-th of 
an inch, which correspond very nearly with the size of those found 
by me in the hver of the fowl. I do not agree with M. Pasteur in 
ascribing to the agency of the atmosphere the various vegetable 
* ' Edinburgh New Philosophical Journal,' 1860. 
VOL. II. T 
