344 PROFESSOR LISTER ON THE GERM THEORY OF PUTREFACTION, ETC. 
or albuminous fluid moculated with this oidium, and in neither of the glass 
gardens, did bacteria, or any other kind of fungus besides the one intentionally 
introduced, make their appearance during the entire month in which the obser- 
vations were made. 
EXPLANATION OF THE PLATES 
Illustrating Professor Lister's Paper on the Germ Theory of Putrefaction and other 
Fermentative Changes. 
Puate XXII. 
Figure 1. A pencil of fructifying threads of the common blue mould Penicillium Glaucum. 
Figure 2. A group of cells of the yeast plant, Torula Cerevisic. 
Figure 3. Bacteria from various sources. The pair below the letter a are examples of a granular 
appearance of the protoplasm, and the presence of a distinct nucleus in each segment. ba | 
Leptothrix filament, some of the segments being nucleated. “on 
Figure 4, Illustrates the ordinary mode of growth of Bacteria, viz., by increase of the segments — 
lengthwise and transverse segmentation. When first sketched, at 7.30 a.m., the object — 
consisted of three segments a,, ¢,, b;. During the few minutes that elapsed between 
the completion of this sketch, and that at 7.42 a.m., the uppermost segment 0, is seen to 
have increased in length to the size shown at b,, and the two lower ones are not only 
longer, but each presents a transverse line of segmentation, while the middle segment is 
bent at this new place of division, c,. Three minutes later the three lowest of the five 
segments of which the object now consisted separated from the other two, and in the © 4 
‘ 
| 

sketch taken at 7.48 they are shown thus detached, the lower two obviously increased in 
length. Two minutes later one of these three was found to have separated and moved off, 
and the remaining pair were observed to swim away as an ordinary double bacterium. 
Figure 5. Represents a minute organism, consisting of granules grouped in a different manner from 
that which commonly prevails among LBacteria. The difference of arrangement is 
explained by difference in the mode of growth, as is illustrated by the sketches ¢,, c,, cg, 
and c, which represent the same granules in process of fissiparous generation. It will be ~ 
observed that the granules, instead of increasing like ordinary Bacteria in one direction 
only, swell up in all dimensions and afterwards undergo segmentation, either into pairs or 
into fours, as indicated in the letterpress, page 319. 
Figure 6. Represents a form of Torula which resulted from the mingling of a drop of rain with fresh 
uncontaminated urine. Appearing in the first instance as an unmixed Torula (a), it 
changed in course of time to a delicate filamentous fungus (6 and c) bearing buds, some of 
which were more or less toruloid in aspect and habit of growth, while others were mor- 
phologically identical with Bacteria, as described in detail in the text. 
x, 
Puate XXIII. 
Represents the same organism (Torula Ovalis), varying in character according to the 
medium in which it grows, and the period during which it has inhabited it. Fora 
detailed description, see letterpress. — 
Puates XXIV., XXV., ano XXVI. 
Show a minute fungus varying according to its habitat, from a filamentous growth to Torule 
of very different characters, all distinctly traced to one and the same organism. . For a 
detailed description, see letterpress. 
These illustrations are all taken from camera-lucida sketches, the magnifying power being 1140 
diameters, except in some cases where it is lower, as indicated by the scales on the plates. 

