608 Original Articles. | Oct., 
In September of the same year, I found this same form in some 
distilled water into which I had washed a little of the dust from my 
study window, and was induced in consequence to examine successively 
dust taken from the high road near my house, which I sprinkled upon 
distilled water, and pure boiled distilled water only, exposed in a clean 
white saucer to the atmosphere. At the furthest, within a week, I 
found (along with others) this little type, its presence in the saucer of 
pure distilled water being accompanied by a slight deposit of dust. 
I followed it in its development 
from the minutest monad, and was 
satisfied at length, from the rhyth- 
mical movements of its “ contractile 
vesicle,” that it was entitled to be 
called a living infusorium. Since 
that time I have repeatedly met with 
it both in pure distilled water and 
in infusions ; and as recently as last 
June, I found it in sufficient num- 
bers in pure distilled water to enable 
Fic. 3.—Different stages in the growth of Mme to include it in the illustration 
Cercomonas fusiformis, or acuminata, found from nature which accompanies this 
by the author in pure distilled water. (C. con- 
tractile vesicles.) paper (p. 613). 
Another form, Ameba Gleichenii, belonging 
(as the protozoa are now classed) to a still 
lower group, was observed by Dr. Balbiani in 
the same infusions with the above-named type, 
and the accompanying is also engraved from his 
original drawing of it. 
Fie, 4.—* Amebu (Gleichenii ?)’—(n. nucleus.) From Dr, Bal- 
biani’s infusions, 
I presume that my coadjutor gave it this 
designation, because the form having the 
| nearest resemblance to it is thus figured by 
™ Dujardin. 
Fie, 5.—Dujardin’s Amoeba Gleichenii. 
If it were fair to criticize the scientific appellations bestowed upon 
these minute particles of organized protoplasm, I should say Dr. 
Balbiani would have done better to give a new specific, title to this 
Ameeba, for it is widely dissimilar from Dujardin’s ; but, be this as it 
may, I have frequently met with similar types in infusions, and last 
June* the same (which I venture to call Balbiani’s) appeared in such 
* Tt is right to state that the cause of my success during that month was the 
high temperature, accompanied by a favourable wind for the conveyance of dust 
into my vessels of distilled water. 
