A flow tremulous motion, confined to one fpot,1 may be perceived
at intervals; this in a little time becomes more lively, and
foon pervades the whole drop.
It’s motions are, in general, very quick; two united together,
may Ibmetimes be feen fwimming among the reft ; while in this
fituation they have been miftaken by fome writers for a different
fpecies, whereas it is the fame generating another by divifion.
It is to- be found in all water, though but feldom in that which:
is pure ; they are in great plenty in the fummer in ditch water,
alfo in infufions of animal or vegetable fubftances, made either o f
frefh or fait water, myriads being contained in a drop; numbers,,
o f various fizes, are to be found in the filth o f the teeth.
The animalcula o f this and the firft fpecies are fo numerous as
to exceed all calculation, though they are contained in a very
confined fpace.
6. Monas Mica.
Monas, circulo notata. Mona, marked with a circle.
This lucid little point may be difcovered with the third lens o f
the common fingle microfcope, when the magnifying power is
increafed ; it appears either of an oval or fpherieal figure, for it
aflumes either at pleafute. It is tra-nfparent, and has a final!
ellipfe inlcribed as it were within it’s circumference; this ellipfe is
moveable, being fometiroes in the middle, fometimes a little towards
the fore-part, at others nearer the hind-part.
5 There
475
There is a confiderable variety in it’s motions ; it often turns
round for a long time in the fame place; an appearance like two
■ kidneys may fometimes be perceived in the middle of the body,
and the animalculum is beautifully encompaffed with a kind of
halo, arifing, moft probably, from invifible and vibrating hairs.
They are to be found in the pureft waters.
7. Monas Tranquilla.
Monas ovata, hyalina, margine nigro. Egg-fhaped, tranfpa*
rent mona, with a black margin.
Thefe animated points feem to be nearly fixed to one fpot,
where they have a vacillatory motion. They are: frequently fur-
rounded with a halo, and differ in their figure, being fometimes
rather fpherieal, at others quadrangular. The black margin is
not always to be found, and fometimes one would almoft be
tempted to think it had a tail. It is found in urine which has
been kept for a time. The urine is covered, after it has remained
in the veflel, with a dark-coloured pellicule, in which thefe animals
live: although the urine was preferved for feveral months,
no new animalcula were obferved therein. It has been already
fhewn, that a drop of urine is in general fatal to other animalcula,
yet we find that it has animated beings of a peculiar kind, appropriated
to, and living in it.
3 M 2 8, Monas