iyS Of the frejh Water Polype* 
The different opening of the mouth and lips, are feen 
%• 343 * 344 - 345 - 
The polype’s mouth opens into its ftomach, forming a 
hind of bag or gut, from head to tail. The naked eye 
may be convinced of this, but much better if it be armed 
with a microfcope. It is exactly reprefented as it appears 
through the microfcope at a b, fig. 262. 
Mr. Trembley not being finished that the polype was 
perforated from end to end, by only obferving it from 
without, cut one tranfverfly into three parts, each piece 
immediately contracted itfelf, and remained very fhort, 
and being all three placed on the flat bottom of a fhallow 
^lafs full of water, and viewed through a microfcope, 
from the upper end, the bottom of the glafs was feen 
through the lower, fo that all the three were vifibly per¬ 
forated ; they are reprefented as they appeared in the mi¬ 
crofcope, by the figures 340. 341. and 342. Its mouth 
was at the anterior end of one of thefe parts a, fig. 340. 
and was then wide open. The posterior extremity was 
at the end b of the third part, fig. 342. as this piece 
was perforated through, it plainly appears, that the tails 
of the polypes are alfo open. 
This perforation which is continued from one end to 
the other of the polype, is called the ftomach, becaufe it 
contains and digefts the aliments, and the (kin which in- 
clofes the ftomach, and forms this bag, is the very fkin 
of the polype. Therefore the whole animal confifts but 
of one fkin, difpofea in the form of a tube or gut, open 
at both ends. 
If a polype be ohferved with the microfcope, its whole 
body appears like fhagreen, or as if it were ftrewed with 
little grains, as reprefented at fig. 362. both vfhen con¬ 
tracted or extended, it is more or lefis varied according 
to thefe or other circumftances. 
If 
