ESSAY ON SPONGES. 



75 



should not organic matter possessing vitality with- 

 out action, exist ? If these philosophers expect 

 to find polypes, or vermes of any kind, to be the 

 inhabitants of Sponges, they will be deceived. 

 The true character of spongia, is that of, a living, 

 inactive, gelatinous flesh, supported by innumerable 

 cartilaginous or corneous fibres or spicula, most 

 commonly ramified or reticulated, and furnished 

 more or less with external pores or small mouths, 

 which absorb the water, and which is conveyed 

 by an infinity of minute channels or capillary 

 tubes throughout every part of the body, and is 

 there decomposed, and the oxygen absorbed as its 

 principal nourishment, similar to the decomposi- 

 tion of air in the pulmonary organs of what are 

 called perfect animals. 



The food of sponges must be similar to that of 

 plants ; for a Sponge has no more power to digest 

 gross bodies, than a Fucus or a Conferva ; and no- 

 thing can be more admirably adapted to a gaseous 

 aliment than the construction of a sponge. The 

 conformation of a sponge, better entitles it to the 

 appellation of sea-lungs, than any other marine 

 production ; since the water absorbed by its capil- 

 lary tubes becomes as greatly divided, as air re- 

 spired by pulmonary organs ; and thus by such 

 an extensive surface offered to the water, decom- 

 position may be effected in the same way as air 

 is decomposed in the lungs of terrestrial ani- 

 mals. 



