SPONGIA OFFICINALIS. 



THE SECONDARY CHARACTERS. 



SPONGIA. Body soft, very elastic, multiform, more or less 

 irregular, very porous, traversed by numerous tortuous canals 

 which open externally by very distinct vents (osculd), and 

 composed of a kind of subcartilaginous skeleton, anastomosed 

 in every direction, and entirely without spicules. 



THE SPECIFIC CHARACTERS. 



SPONGIA OFFICINALIS. Masses very large, flattened and 

 slightly convex above, soft, tenacious, coarsely porous, cracked, 

 and lacunose, especially beneath. Vents sound, and for the 

 most part large. 



NATURAL HISTORY. 



The great circles to which the animal and vegetable king- 

 doms are compared, like the smaller circles, touch each other ; 

 that is, there are certain forms of organization so closely allied 

 to both, that it is difficult to say precisely in which they ought 

 to be included. Such are the sponges, which, although by 

 common consent admitted into the animal series, will be found 

 to be excluded, by almost every point of their structure, from 

 all the definitions of an animal hitherto given. The con- 

 cise axiom of Linnaeus upon this subject is well known : 

 " Stones grow, vegetables grow and live, animals grow, live, 

 arid feel." The capability of feeling, therefore, formed in the 

 opinion of Linnseus the great characteristic separating the 

 animal from the vegetable kingdom ; yet in the class under 

 consideration, no indication of sensation has been witnessed; 

 contact, however rude, excites no movement or contraction, 

 which might indicate its being perceived; no torture has ever 

 elicited from them an intimation of suffering. Sponges have 

 been pinched with forceps, lacerated in all directions, bored 

 with hot irons, and attacked with the most energetic chemical 

 stimuli, without shrinking or exhibiting the remotest appear- 

 ance of sensibility. On the other hand, in the vegetable world 

 there are plants which apparently feel, in this sense of the 

 word. The sensitive plant, for example, which droops its 

 leaves upon the slightest touch, has far greater claims to be 

 considered animal than the sponges of which we are writing. 



The power of voluntary motion has been appealed to as 

 exclusively belonging to the animal economy ; yet, setting 

 aside the spontaneous movements of some vegetables, the 



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