Of the frejh Water Polype . ipg 
This extremity is often terminated by a knob, and the 
hairs marked e, e, e, fig. 364. 365. are tranfparent, and 
may be feen with the firft and fecond magnifiers. 
The beft method to obferve a polype’s arm, is to choofe 
one that is fixed to the fide of a glafs, and near the fuper- 
ficies of the water: at which moment, any one of its 
arms being very well extended, take a pair of nippers in 
one hand, and a flip of glafs, about two or three inches 
long, and half an inch broad, in the other, holding it at 
one end between the finger and thumb; then with the 
nippers, or a pointed quill, pull the end of the arm gently 
out of the water, and the reft will follow. If it is not 
ftretched enough, ftretch it more, by drawing it out, the 
polype ftill remaining fixed to the glafs; put the arm 
upon the flip of glafs, and turn it under till it meets itfelf 
again; then giving it a jirk, the arm will break ofr on 
both fides the flip of glafs, one part remaining with the 
polype, and the other in the forceps, and the middle part 
will ftick upon the glafs flip, in which manner it may be 
applied to the microfcope, and preferved for feveral days, 
as well as when it is at firft taken out of the water, 
for when once dry it does not change for a confider- 
able time. 
Of the polypes food, and manner of their 
feizing upon, and {wallowing their prey. 
I T was forae time after the difeovery of the fecond 
fort of polypes, before Mr. Trembley could find out 
a proper food to nourifh them, but the water at that 
time happened to be plentifully ftored with a fort- of 
millepedes, fig. 360. final 1 enough, and about three 
quarters of an inch in length. They are remarkable 
N 2 fof 
