C 784 ] 
ct fomething transparent, by the projedion of a ledge 
<c inverting the whole circumference about the middle 
of its depth, and not to be extracted without fome 
<f force. That each fucker is fattened by a tendi- 
tc nous ftem to the arm of the animal : which ttem, 
tc together with part of the membrane that is below 
tc the circumference of the cartilaginous ring, rifes 
“ into and fills the whole cavity when the animal 
<c contracts the fucker for adion. In this ttate 
<c whatever touches it is firft held by the minute 
<c hooks, and then drawn up to a clofer adhefion by 
“ the retradion of the ftem and inferior part of the 
<c membrane, much in the fame manner as a fucker 
“ of wet leather fuftains the weight of a fmall ftone.” 
Vid. MicroJ'copical Difcoveries , p. 22. 
M fhews one of the cartilaginous rings armed with 
fmall hooks, of its real fize. The ring this is drawn 
from was taken out of a large fucker of a larger Po- 
lypus, and is prefented herewith. 
By thefe fuckers the Polypus can fix itfelf to rocks, 
and prevent its being totted about in ftorms and tem- 
pefts; but their principal ufe mutt undoubtedly be to 
leize and hold its prey : and to this purpofe they are 
moft admirably adapted ; for when they are all ap- 
plied and ad together, unlefs the Polypus pleafes to 
withdraw them, nothing can get from it whole 
ftrength is infufticient to tear off its arms. Some- 
thing like thefe fuckers is found by the microfcope 
in the minute frefh water Polype, whereby it is able 
to bind down and manage a worm much larger and 
feemingly ftronger than itfelf* *. In like manner the 
* Of this I gave an account fome years ago, in my attempt 
towards a Natural Hiftory of the Polype, chap, v. 
• ft el la 
