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“ Thefe fponges,” he fays, confift of hard firm 
** fibres, twifted about in doubles, and the interftices 
filled with a mucilaginous gluey matter, having large 
“ hollows, with cylindrical tubes, difperfed through 
“ their fubflance/ forming a kind of labyrinth filled 
“ with thefe worms. 
He fays, he has obferved, “ that the fponges be- 
gin to be formed on a nodule of petrified fand or 
“ other like matter, round which the worms begin 
to work, and round which they retire as to their 
lafi; feat or refuge. 
He then proceeds to ^ve a defeription of 
them, which is, “ that they are 4- of a line thick, 
“ two or three lines long, of a conic figure, with a 
“ fmall black head furnifibed with two pincers j the 
“ other extremity is fquare, and much larger than 
the head ; their motion begins at the tail, and ends 
** at the head j they are fo tranfparent, that the cir- 
** culation of the blood may be perceived ; and 
“ where the vifeera Ihould be, there is a kind of 
circular motion of a blackifh matter moving to 
“ and fro in the animal. He fays, he has kept 
“ them alive more than an hour out of the f^nge, 
“ and (which is very fingular) when he put them 
“ near a piece of frelh fponge, where the nefts were 
“ moift, and from which he had before pulled them, 
“ he faw them enter and difappear. He goes on 
** to tell us, that thefe worms have no particular 
“ lodge ‘y that they walk indifferently into the tubu- 
lar labyrinth ; fo that, he fays, without offence to 
Pliny and other naturalifts, he does not fee that it 
“ is in their power to dilate and contrad: the bodies 
of fponges, which always remain in the fame fiate 
“ of 
