a tk , feenas contracted at i. The fimbrillae, or little hairs, may
be feenin molt o f the attitudes, except thofe o f 1.
O f t h e H y d r a S o c i a l i s .
H y d r a s o c i a l i s m u t i c a t q r o s a r u g o s a . F ig . n , P I. XXL
Bearded thick and wrinkled.
This fpecies of hydra has been defcribed by many writers. It
is the vorticella focialis of Muller, who defines it as vorticella
caudata, aggregata, clavata; difco obliquo Muller Animalcula
infuforia, p. 304. Pallas makes it a brachionus, Pall. Zooph. 53.
In Fig. 11 thefe animals are jeprefented as confiderably magnified
; they appear like a circle, furrounded with •crowns, of
•ciliated heads, tied by fmall thin fails to a common center, from
whence they advance towards the circumference, where they turn
like a wheel, with a great deal o f vivacity and fwiftnefs, till they
occafion a kind o f whirlpool, which brings into it’s fphere the
proper food for the polype. When one o f them has been in motion
for a time, it hops, and another begins ; fometimes two or
three may be perceived in motion together. They are often to
be found feparate, with the tail flicking in the mud. The body
■ eontrafits and dilates very much, fo as fometimes to have the appearance
o f a cudgel, at others to aflume almoft a globular form.
The young polypes o f this fpecies have been fometimes taken for
the hydra fientorea.
O f THÈ VORTlCEELié.
We now Confié to another dmfiori of thefe animals, to which
later writers have given the name of vorticellæ, which we lhall
therefore adopt, as we think it behoves every man to maintain
that order in fcientific arrangement which is not inconfiltent with
truth, except he can produce another arrangement more ex-
preffive o f the nature of the objects it is defigned to difcriminate.
The variety that may be obferved in thefe minute animals, confirms
a principle, which the more it is looked into, the more it
will be found tb aCcófd with thé general operations in nature,
namely, that there is always a pre-éxiftent principle of life
neeelfary to the organization both o f animals and vegetables ;
that the alimentary and other particles which are added to, or apparently
belong to them, produce nothing o f themfelves, they are
incapable o f forming the leaft fibre, bttt they are able to becomé
conflituent parts o f one organical whole, and the inffrumênts
whetëby the forming principle is manifelledj and rendered: Capable
o f acting upon certain orders o f creatures.
V o r t i c e l l a .
Animal, calyce vafculofo ; ore contraótili ciliato, terminali
ftirps fixa.
A fmall animal, with a vafCülar cup ; the mouth is at one end
ciliated, and capable o f being Contracted, the Item fixed.
3 G V0RT1-