298 ON THE GERM THEORY OF PUTREFACTION 
now of spherical form destitute of vacuoles, but strongly nucleated, as shown 
at /, Plate IX, and disposed in considerable irregular groups, as seen in the 
outline portions of the sketch. The same character was maintained by the scum 
in this glass during the rest of the time (fifteen days) that it was kept under 
observation, m being a sketch of its appearance after the lapse of ten days ; so 
that the organism had assumed completely the appearance of a spherical torula. 
But it may be asked, Was I not deceived in supposing that the new toruloid 
form in the second inoculated glass had anything to do with the oidium? May 
it not have been a totally different species accidentally present, just as the oidium 
itself was apparently adventitious in the yeast-glass ? That all the oval cells 
should have disappeared within twenty-four hours, and given place to another 
species producing a scum of the same remarkable naked-eye appearance, seemed 
indeed very improbable ; but, on the other hand, the difference of character in 
the cells was so remarkable, that if it was really only due to a modification of 
the same organism, it was desirable, if possible, to place the fact beyond doubt. 
With this object, on the 30th of August, I mingled a morsel of the scum, by means 
of a ‘ heated’ glass rod, with a drop of Pasteur’s solution! on a ‘heated’ slip of 
glass, and placed upon it a “ heated’ piece of thin covering glass, and over this 
a larger plate of thin glass also ‘heated’, overlapping the former one well on 
all sides, and luted down the margins of the upper glass with melted paraffin, 
applied with a hot steel pen. The object of this arrangement was that, while 
evaporation should be prevented by the paraffin luting, the interval between 
the thin glass plates might contain a supply of air to permit the growth of the 
fungus. I then selected for observation a group of the spherical cells near the 
edge of the liquid, and therefore near the air between the plates, and sketched 
them with camera lucida, as shown at 1,, Plate IX. This was at 5.50 p.m. 
At 6.8 p.m., I noticed a change in the nuclei of the cells, such as I have often 
observed in spores preliminary to germination, as indicated at 7,, and by II p.m., 
the object being still undisturbed under the microscope, the lowest of the cells 
had not only increased in size, but had produced a considerable elongated sprout 
(see ,), while the other cells were all markedly changed in the character of their 
nuclei. At midnight the sprout from the lowest cell had itself produced another 
sprout, also of oval form (see 1,), and by 7.45 next morning, when I next looked 
at the object, two other cells had been produced from the last sprout, while 
some, if not all the other cells of the group, had also germinated, giving rise to the 
appearance shown at m;. And it will be observed that the products of this 
growth of the cells of the scum were not spherical and nucleated like them, 
* The Pasteur’s solution contained 1 per cent. of alcohol, for reasons with which I need not trouble 
the reader. 
