Of the frejh V/ater Polype. 177 
If the lips of a polype be cut tranfverfly and placed 
upon the objedt-carrying glafs, in fuch a manner as that 
the cut part of the fkin a, fig. 341. may lie dire&ly be¬ 
fore the microfcope, it will be found to confift of an in¬ 
finite number of thofe little grains throughout the whole 
thicknefs of the fkin : therefore, in order to know whether 
the infide of the flomach had any of the like grains, Mr. 
Trembley opened feveral of them in the following man¬ 
ner ; by putting a polype upon his hand, he made it, by 
touching, to contrail: as much as poflible, and then he 
introduced a very fine point of a pair of fciflars into its 
mouth, and forcing it out at the tail, and immediately 
doled the fciflars, which cut one fide of the polype’s fkin 
from the top to the bottom, and laying it open from one 
end to the other difcovered the interior fuperficies thereof, 
which is reprefented as it appeared in the microfcope at 
fig. 346. and this was alfo compofed of as great a quan¬ 
tity of the fame grains as the exterior fuperficies and the 
edge a, of the cut piece of fkin, fig. 346. To examine 
thefe particulars a little farther, a bit of the fkin was 
laid upon a glafs Aider in a drop of water, and placed 
before the microfcope, a, fig. 347. and fome of thefe 
grains fepaiated therefrom, as at b, c, d, by prefling 
them with the point of a pin, ftriking them againfl: the 
glafs, and endeavouring to tear them in pieces ; the grains 
fpread themfelves to all parts of the water, and at laft 
remained in heaps as at e and f. 
If a polype be carefully placed before the microfcope, 
fo as not to wound him, you will feldom be difappointed 
of feeing thofe grains feparate from fome part or other, 
and that in the moft healthy polypes ; but when they 
feparate in large quantities, it is a certain fymptom of a 
dangerous illnefs. The furface of the polype from which 
they fall becomes irregular, and is no more terminated as 
N before. 
