THE YOUNG SCIENTIST. 
41 
tremely mobile toes attached to his tail- 
foot. Then came a creature swimming 
like an otter, thrusting his head about on 
all sides, and looking much more intelli- 
gent than most of his compeers of the 
pond. Looked at vertically, he was some- 
what slipper-shaped, the rounded heel 
forming his head, then narrowing to a 
waist, and expanding towards the other 
end, which projected in a fork. All round 
him were long cilia, wLich were conspicu- 
ous near the head, and a line line indicated 
the passage from his mouth to the stom- 
ach, which seemed full of granular matter. 
Presently he took to crawling, or rather 
running, over a thread of conferva, and 
then his back was elegantly arched, and 
his cilia stood erect like the quills of a 
porcupine. This was the Chcetonotas 
larus. 
ChaBtonotus larus (crawling) X520. 
In Pritchard's *' Infusoria," the views of 
those writers are followed who rank this 
animal amongst the Kotifers, and place it 
in the family Icthidina. To help out this 
theory, the cilia upon the ventral surface 
are imagined to form a "band-like rotary 
organ ; " but in truth they bear no resem- 
blance whatever to the so-called wheels of 
the ordinary Rotifers, nor is there any- 
thing like tlie gizzard which true Rotifers 
present. Ehrenberg treated it as a Ro- 
tifer, and Dujardin placed it among the 
Infusoria, in a particular class, compre- 
hending symmetrical organisms. The 
" Micrographic Dictionary" remarks that 
its " structure requires further investiga- 
tion,"* and while the learned decide all 
the intricate questions of its zoological 
rank, the ordinary observer will be 
pleased to watch its singular aspect and 
lively motions. Its size, according to the 
" Micrographic Dictionary," varies froiii 
1-710" to 1-220", and while its general pro- 
ceeding may be watched with an inch or 
two-thirds object glass, and the second 
eye-piece, a power of five hundred linear 
(obtained by a quarter or a fifth) is re- 
quired to make out the details of its 
structure. If placed in a live-box with 
threads of conferva, and a little decayed 
vegetation, it may be observed to grope 
* See a valuable paper by Mr. Gosse, "History 
of the Hairy-baoked Animalcules," Intellectual 
Observer, vol. v., p. 387, in which the known 
species are described and reasons given for fol- 
lowing Vogtand ranging them with the Turbella- 
nan worms. 
about among them, and shake them like 
a dog. 
We have said that water-fleas were 
among the inhabitants of a bottle filled at 
the pond, and as they go the way of all 
flesh, it is common to find some odd-look- 
ing animalcules ready to devour their 
mortal remains. These are creatures 
shaped like beer-barrels, upon short legs, 
and which swim with a tubby, rolling gait. 
Looking at one of these little tubs length- 
wise, a number of lines are seen, as though 
the edge of each stave projected a little- 
above the general level, and transverse 
markings are also apparent, which may 
be compared to hoops. This is the Colepi$ 
hii'tus, which differs from the usual type 
of Infusoria, by being symmetrical, that 
is, divisible into two equal and similar 
halves. The dimensions of this species 
vary from 1-570 to 1-430, and its color 
varies from white to brown. It has been 
observed to increase by transverse self- 
division, and has two orifices, one at each 
end, for receiving food and ejecting the 
remains. It often requires some little 
trouble to get a good view of the cilia, 
which are arranged in transverse and 
longitudinal rows. A power of one hun- 
dred and fifty linear is convenient for 
viewing it in motion, but when quiet under 
pressure, one of five or six hundred may 
be used with advantage. 
Coleps hirtus. 
Among the rubbish at the bottom of the 
bottle, in which the coleps was found, was- 
a minute dead Rotifer, the flesh of which 
was fast disappearing, but upon being ex- 
amined with a power of nine hundred and 
sixty diameters, it was observed to swarm 
with extremely minute vibriones, the 
largest only appearing under that im- 
mense magnification like chains of bluish- 
green globules, not bigger than the heads 
of minikin pins, while the smallest were 
known by a worm-like wriggling, although 
their structure could not be defined. 
These vibriones are probably members of 
the vegetable world, and they always ap- 
pear when animal matter undergoes putre- 
faction. 
M. Pasteur has brought forward elabor- 
