have imagined them to be mere vegetables ; but that 

 they are really poffeffed of a living principle is evident 

 from the circumftance of their alternately contracting 

 and dilating their pores, and fhrinking in fome degree 

 from the touch when examined in their native' waters. 

 In fhort, fponges confift of an infinitely ramified mafs 

 of capillary tubes, poffeffed of a certain degree of con- 

 tractile power, and capable from their ftrudture, of 

 abforbing nutriment from the furrounding fluid in 

 which they are by nature immerfed. They therefore 

 form an animal tribe different from all others, and may 

 be confidered as the moll torpid of all Zoophytes. 

 The different fpecies of Sponge differ greatly in ap^ 

 pearance from each other : fome being amorphous, or 

 of no regular fhape, as the common or officinal fponge : 

 others cyathiform or eup-lhaped : others tubular, and 

 of various forms ; and fome are ramified and reticulated 

 in fuch a manner as to bear a confiderable refemblance 

 to the fea-fan or Gorgonja Flabellum of Linnaeus. The 

 fpecies here exhibited, as an example of the genus, is 

 found both in the Mediterranean and Indian feas ; ad- 

 hering, like others of its genus, to rocks. In fize it 

 varies from a few inches in diameter to that of a foot 

 or more. Its colour is a pale brown, and its fubftance 

 lefs ftrong or tenacious than that of the common or 

 officinal fpecies. 



