Of Animalcula in Fluids . 
and befet with hairs, but both ends tranfparent, their 
tails tapering with a long fprig at the extremity thereof, 
their motion flow and waddling. 
Of animalcula in a cold infulion of fenna. 
A Bout the middle of July, as much as could be taken 
up with two or three fingers of the leaves, {talks, 
and branches of fenna, was put into cold water, and in 
about eight days, the furface thereof was ftored with ex¬ 
tremely minute longifh bodies, feparate from each other, 
but without motion. The corpufcles reprefented at fig. 
214. were thought to be nothing elfe but pieces of the 
bark from the branches of the fenna; but in about eight 
days after, they all difappeared, and a furprizing number 
of worm-like animalcula fucceeded them, but lefs than 
the firft, being alive, and fwimming a little below the 
furface of the water; one of thefe worms is feen at fig. 
215. Its head round at I, its body compoibd of eleven 
ringlets, the loweft extremity of which ends fometimes 
in a plain perpendicular to its body. At other times with 
■three round protuberances, as at M. 
Through the {kin there appears a very white fibre, 
branching as it were from each fide of the tail, in a ftrait 
line towards the head, where they unite in an arch, as 
at N, fig. 216. This fibie extends and contracts itfelf 
alternately, by which means the ringlets are drawn nearer 
to, or pufhed farther from each other. Part of the water- 
being evaporated by its {landing feveral days, a little 
frefh water was poured thereon, which caufed the {kin 
that fwarn on the furface of the infufion to fink to the 
bottom of the veffel j the infufipn was thereby refined, 
and inoie trail iparent than it was before, which occafioned 
k 3 the 
