THE YOUNG SCIENTIST. 
67 
ing rotifer, the OEcistes crijstallinus, which, 
although less beautiful than the Flos- 
cules or the Melicerta, is. nevertheless, a 
l)retty and interesting object. In this 
instance a little rough dirty tube, about 
1-70" long, was observed to contain an 
animal capable of rising up and expand- 
ing a round mouth garnished with a 
wreath of cilia ; while a little below, the 
indefatigable and characteristic s^izzard 
OEcistes crystalliiius. X 240. 
of the tribe was in full play. A power of 
two hundred and forty linear sufficed to 
afford a good view, and it was seen that a 
long, irregular, conical body was sup- 
ported upon a short wrinkled stalk. The 
usual drawings represent this creature 
with a short bell-shaped body upon a 
very long slender pedicle. Possibly this 
one might have been able to show himself 
under this guise, but he did not attempt 
it; his appearance being always pretty 
much as described, which made the foot 
shorter and the body longer than the 
measurements which naturalists have 
given, and according to which the whole 
creature is 1-36" long, although the body 
is only 1-140". The tube of the CEcistes 
IS called a "lorica," or carapace; but it 
has in truth no right whatever to the ap- 
pellation. 
Another strange rotifer, of whose name 
I am uncertain, had an ovalish oblong 
body, and a pair of legs like compasses, 
twice as long as himself. His antics were 
those of a posture-master, or "Professor 
of Deportment " on stilts. Sometimes he 
stood bolt upright, bringiDg his legs close 
together ; then they were jauntily crossed, 
and the body carried horizontally ; then 
the two legs would be slightly opened, 
and the body thrown exactly at right 
angles to them. These antics were re- 
peated all the while the observation 
lasted, and had a very funny effect in 
proving that drollery is practiced, if not 
understood, in the rotatorial world. 
Another kind of rotifer was abundant — 
the Fhilodina, which belongs to the same 
family as the common wheel-bearer, 
namely, the Philoclincea. The Philodina 
is a good deal like the common wheel- 
bearer, or Botifer vulgaris, but is usually 
of a stouter build, and carries his eyes in 
Philodina (swimming). 
a different place. In the common rotifer 
these organs are situated on the pro- 
boscis, while those of the Philodina are 
lower, and said to be "cervical." The 
changes of form in this rotifer are still 
more remarkable than in the common 
wheel-bearer. When resting it resem- 
bles a i:)ear-shaped purse, puckered in at 
the mouth. Then it thrusts out its tail- 
foot, swells its body to an oval globe, pro- 
trudes its feeler, and slightly exposes a 
row of cilia. After this two distinct 
wheels are everted, and as their cilia 
whirl and spin, the animal is swiftly 
rowed along, until it thinks proper to 
moor itself fast by the tail-foot, and em- 
ploy all its ciliary power in causing cur- 
rents to converge towards its throat. 
When it pleases it can elongate the body, 
till it becomes vermiform, and it walks 
like the common rotifer, by curving its 
back, and bringing its nose and its tail 
in contact with the ground. 
Philodina (crawling). 
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