iS2 S P O N G I A. 



At fig. 2. is a magnified part of the ftem of the Sertu- 

 laria, with fome of the wart-fhaped cells of the Alcyo- 

 nium upon it. 



XVI. SPONGIA. SPONGE 



Animal Jixum, flexile^ Is an animal that is fixt, 



polymorphum, torpidijfi- flexible, and very torpid, 

 mum^ contextum vel e Ji- growing in a variety ol forms, 

 bris reticulatisy vel e fpi- compofed either of reticulated 

 nulisy gelatina viva vef- fibres, or maffes of fmall fpines 

 titis ; interwoven together, which 



are clothed with a living gela- 

 tinous fleffi full of fmall 



OtcvXis feu foraminibus mouths or holes on its furface, 

 fuperficiei aquam re/pi- by which it fucks in and 

 rans. throws out the water. 



As to the nature and formation of Sponges, I mall re- 

 fer the reader to my letter on this fubject, addreffed to 

 Doctor Solander, publimed in the Philofophical Tranfac- 

 tions, Vol. 55. p. 280. I fhall only add, that the tex- 

 ture of them is very different in different fpecies ; fome 

 being compofed wholly of interwoven reticulated fibres, 

 when others are compofed of little maffes of ftrait fibres 

 of different fizes, from the moft minute fpiculas to ftrong 

 elaftic mining fpines, like fmall needles of one-third of 

 an inch long; befides thefe, there is an intermediate fort 

 between the reticulated and the finer fafciculated kinds, 

 which feem to partake of both forts. 



But I muff obferve here, that thofe that are compofed 

 of the ftronger and larger bundles of elaftic fibres, like 



needles, 



