l yo Of the frefh V/ater Polype 
% S 3 1 - at a and e > %* 33 2 * anci at a > fi g* 333 • and 334 * 
The number of their horns in thefe three forts of polypes, 
is generally at leaft fix, and at moft twelve or thirteen, 
yet neverthelefs there are fome few of the fecond fort 
which have eighteen arms. They can contrail their bo¬ 
dies till they are not above the tenth of an inch or 
thereabouts in length : for example, that reprefented at 
fig. 333. could contract itfelf fo as to become like thofe 
two reprefentations fig. 335* They can alfo {fop at any 
degree either of extenfion or contraction, from the greateft 
to the leaft. 
The green ones are generally about half an inch in 
length when ftretched out. Thofe of the fecond and 
third fort are moft commonly between three quarters of 
an inch and an inch; but fome may be found of both 
forts, whofe bodies are an inch and half long. 
They grow fmaller as they extend, and increafe in 
bulk as they contrail themfelves. The figures 331. 332. 
and 333. reprefent the general and natural fize of thefe 
three forts of polypes - 3 and at fig. 362. is an exail repre- 
fentati%i of one, as it appears in the microfcope. 
You may oblige them to contrail more or lefs, in pro¬ 
portion as they are touched, or as the water in which 
they are, is agitated more or lefs. Every polype, when 
taken out of the water, contrails itfelf in fuch fort, as 
to appear like a mere lump of jelly on the body it is 
faftened to, as at fig. 336. which figure is fo different 
from what it bears when ftretched out, that it can fcarce 
be known at firft fight, but when the eye is once ac- 
cuftomed to it, they are eafily diftinguifhed from all other 
bodies that are out of the water. 
Heat and cold hath the fame effeils on the polypes, as 
ft hath upon all other land and water infeits. Heat 
animates, and cold benumbs, or makes them faint and 
languid 3 
