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commas, and not a single minute segment, such as would be produced 
if the deep notches had completed division across the body of the 
organism without further change. Nor am I able to say whether 
the nipped-off little bodies grew and took on the same form as the 
parent, or in the future might be the origin of a pleomorphism not 
hitherto noted, as far as my knowledge extends. 
These minute details have been more particularly dwelt on for the 
reason that some such changes may perhaps, by constant observation 
under varied conditions, be shown in the spirillum of Asiatic cholera, 
or in other spirilla. 
Dr. Henri Van Heurck has already pointed out that in the ends 
of the commas of the cholera bacilli he considered he could, by his 
objective N.A. 1*6, and by employing its attendant requirements, 
find a differentiated spot at each end of the comma segment, but 
naturally he is, when speaking of such a very minute object, cautious 
not to dogmatize on its nature. Possibly the observations herein 
recorded may tend to show that we have yet something to learn about 
the different spirilla. 
During the time of my engagement on this subject I was fortunate 
to find in some water, foetid from decomposing vegetable and infusorial 
matter, a spirillum which from the shape of the segments I supposed 
to be Spirillum volutans, knowing it is often found in stagnant pools. 
Though the water was very clouded and dirty, a photomicrograph 
was made of one of the long filaments having also three segments in 
the same field, as shown in the photomicrograph No. 4. There it 
can be seen that the entire plasm has become differentiated both in 
the long filament and single segments. All were active when first 
placed under the Microscope. This photograph was taken with a 
Gundlach 1/14 (about) water-immersion. The plan adopted to fix 
the objects has generally been by a saturated solutien of tannic acid 
run under the cover, and the staining by a saturated solution of iron 
sulphate with 10 grains of citric acid to the ounce of solution — no 
heat being employed in any stage. Preference was given to this 
method to differentiate the delicate shadings of the interior plasm 
over any of the anilin dyes, especially as the resulting tint is a fair 
one for photographic purposes. 
I have been rather puzzled to ascertain how the swarming or 
resting colonies were formed, so many of the organisms being placed 
symmetrically, when apparently there was no visible reason for such 
an arrangement — if not a physical one, as many of the commas were 
provided with flagella, therefore with the means of motion. This 
swarming or colonizing period, one of rest, may be one of the neces- 
sary conditions for trying to tide over adverse circumstances, if not 
one of necessity prior to subsequent higher biological changes. Much 
trouble was taken to try and obtain, at different times, a similar stock 
from the same slaughter-house, but without success, so that I have 
been unable to continue these observations, and the basin containing 
