4 Mv. II. J. Carter on the Anatomy 



It may be said to be not so applicable as the term " Porifera," 

 which has also been used for sponges ; but in the promulga- 

 tion of knowledge of whatever kind, as well as of opinion, it 

 is an established principle not to scare away by new names 

 and new things, but to retain as much as possible of the old, 

 that the human mind may be tempted to receive that which 

 under an unaccustomed appearance it might reject. Thus 

 many a good system has never been generally adopted, because 

 it has involved an entirely new nomenclature. 



A sponge, in the common acceptation of the word, is the 

 fibrous portion or skeleton of a pulp-like mass, and is analogous 

 to the fibrous skeleton or support of a vegetable whose pulpy 

 or soft parts have been washed or rotted away by putrefaction 

 {ex. gr. hemp) ; only, in the first instance the fibre is horny 

 (that is, of an animal), and in the latter woody (or of a vege- 

 table nature). The skeleton of the sponge of commerce is 

 resilient ; but that of many Spongida is not so ; and there are 

 some in which it is glass-like and rigid ; while in others it is 

 altogether wanting, there being apparently no skeleton at all, 

 and the whole mass, with the exception of the dendriform 

 plexus of the excretory canal-system, is a simple pulp. 



Sponges grow only under water and in the sea, all over the 

 world (that is, as far as our geographical discoveries have 

 extended), in the torrid as well as in the frigid zones; but 

 as with plants and animals, so with sponges, particular ones 

 are only to be found in particular localities. Thus the sponge 

 of commerce is chiefly obtained from the Levant &c. 



Again, they grow on hard bodies, such as rocks, or on soft 

 ground, such as sand or mud : the rocks may be in deep or 

 in shallow water ; and so may be the soft ground. When 

 growing on rocks, they for the most part fix themselves by 

 flat expansion or root-like extension to the upper or under 

 surface ; and when on sandy or muddy ground, by root-like 

 extensions alone projected into the sand or mud. When 

 growing on the under surface of the rock towards shore or 

 in submarine caverns, they may be pendent ; and this is their 

 wonted position and chief habitat ; but when on the ground or 

 on the surface of the rock, they are of course erect. Although 

 for the most part preferring fixed objects, some kinds are found 

 growing over shells which, from their kind, never could have 

 been stationary ; and some on the fronds of Fuci, which never 

 could have been still, but ever waving in the Laminarian 

 zone. 



Again, some sponges grow both on the under and upper 

 surfaces of rocks respectively of this zone, others in similar 

 positions further out in the shallow seas, and others similarly 



