AND OTHER FERMENTATIVE CHANGES 303 
stink, and that, where it was evolved in a limited space confined between the 
two plates of glass, it accumulated and produced its effect upon the plants. 
When, on the other hand, it was formed in the very thin film of liquid, which 
alone accompanied the plant on the roof of the air-chamber, it escaped into 
the air as fast as it was produced, and left the fungus unchanged. And this 
view is strongly confirmed by another fact, which I observed at the time when 
the glass garden was stocked (on the 11th of September), viz. that in the first 
urine-glass the filamentous form of growth, which had been entirely suspended 
four days after inoculation, was again present in abundance, forming little woolly 
tufts, which studded the side of the glass. In other words, the urine had been 
restored to a condition compatible with the filamentous mode of development ; 
and the natural explanation of this occurrence is, that the substance which 
exerted the modifying influence upon the organism, stimulating the corpuscular 
while checking the filamentous formation, was a volatile product of fermentation 
of some constituent of the liquid present in limited amount, and that when 
this constituent was exhausted, and the volatile product had escaped, the 
organism was again at liberty to form filaments, as it would have done if placed 
in fresh urine. 
The investigation with the ‘ glass garden’ had thus abundantly proved that 
the filamentous fungus seen in the glass of Pasteur’s solution, the pairs of oval 
vacuoled corpuscles of the primary scum in urine, and the spherical nucleated 
cells of a later period, were one and the same organism, modified by circum- 
stances ; while in the last-named variety we have another example of a plant 
presenting for weeks together the character of a pure and unmixed torula, 
which, had I seen it only in that condition, I should have considered as much 
entitled to that generic name as the yeast plant, yet rigidly demonstrated to be 
a conidial development of a filamentous form. Comparing it with the Torwla 
Ovalis, there is this curious difference between them, that whereas in the latter 
fresh urine is a medium in which the toruloid form especially flourishes, the 
filamentous growth making its appearance in it only when the liquid has been 
altered by the fermenting influence of the organism, the converse is the case 
with this plant. The present species, like the Torula Ovalis, failed to effect the 
ammoniacal fermentation of urea, the contents of the second urine-glass being 
found still sharply acid on the 5thof November, ten weeks afterinoculation. Yet 
it is, as we have seen, an energetic putrefactive ferment of some of the urinary 
constituents, and on this account is attended with considerable interest. And 
as the remarkable naked-eye appearance of the scum which it forms in that 
liquid when altered under its agency, and the toruloid character of the con- 
stituent cells, appear to furnish sufficiently definite specific characters, it seems 
