THE YOUNG SCIENTIST. 
133 
A Common Microscopic Object. 
AMONGST the most common, as well as 
the most interesting of microscopic 
objects are the bell-shaped animalcules 
(Vorticella nehulifera). They are to be 
found in almost every pool of water, and, 
indeed, in every old bucket used to draw 
water from wells and cisterns. They are 
therefore amongst the first objects which 
present themselves to young microscopists, 
many of whom, when they first see them, 
little hair-like processes which are seen to 
fringe the mouths of the bell- shaped cups 
in the engraving, requires a good glass. 
The word cilia means literally eye lash, and 
these lashes when put in motion create a 
sort of whirl-pool or vortex, which sucks in 
any little floating particles, and carries 
them into the interior of the animalcule, 
any nutriment that they may contain being 
absorbed, and the insoluble parts rejected. 
These cilia are put in motion one after the 
other in a continuous round, and this gives 
an optical appearance exactly like the mo- 
tion of a wheel. A similar effect in another 
GKOUP OF BELL-SHAPED ANIMALCULES {VorticeUa NebuUfeva). 
think they have discovered a new organism 
of rare and surpassing beauty, for they 
cannot see how a creature so exquisite and 
interesting can be known at all, and yet not 
be known to everybody. Those who desire 
to study the life history of these curious 
creatures, will find a pretty full account of 
them in Gosse's "Evenings with the Micro- 
scope," and in Carpenter's treatise. It 
requires no great power to see the animal- 
cules themselves, or even to detect the 
curious wheel-like motion of their cilia, by 
means of which they obtain their food, 
but to see the cilia themselves, that is, the 
and nearly allied organism, has given it the 
name of the wheel animalcule. These little 
I creatures are very sensitive, and the least 
jar produces a curious effect upon them. 
They at once stop all motion, and the long 
stalk upon which they are mounted in- 
stantly contracts, assuming the spiral form 
seen in two of the individuals shown in the 
engraving. After a short time they again 
begin to expand, the wheels resume their 
motion, and the process of feeding goes on 
as before. No one ever sees this object for 
the first time without being enchanted 
with it. 
