OCEAN LIFE. 



PORIPHORA. 



THERE are certain forms of organization so closely allied to 

 both the animal and vegetable kingdoms, 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 devised. What is an animal? How are we to distin- 

 guish it as contrasted with a mineral or a vegetable ? The con- 

 cise axiom of Linnaeus upon this subject is well known : " Stones 

 grow; vegetables grow and live; animals grow, live, and feel." 

 The capability of feeling, therefore, formed, in the opinion of 

 Linnaeus, the great characteristic separating the animal from the 

 vegetable kingdom; yet, in the class before us, no indication of 

 sensation has been witnessed ; contact, however rude, excites no 

 movement or contraction which might indicate its being per- 

 ceived; no torture has ever elicited from them an intimation of 

 suffering; they 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 appearance of sensibility. 



On the other hand, in the vegetable world we have plants 

 which apparently feel, in this sense of the word. The sensitive 

 plant, for example, which droops its leaves upon the slightest 

 touch, would have far greater claims to be considered as being 

 an animal than the Sponges, of which we are speaking. The 

 best definition of an animal, as distinguished from a vegetable, 

 which has yet been given, is, that whereas the latter, fixed in the 

 soil by roots, or immersed perpetually in the fluid from which it 

 derives its nourishment, absorbs by its whole surface the nourish- 

 ment which it requires ; the animal being, generally, in a greater 

 or less degree capable of changing its position, is provided with 

 an internal receptacle for food, or stomachial cavity, from whence, 

 after undergoing the process of digestion, the nutricious matter 

 is taken up. But, in the case of the Sponge, no such reservoir 

 is found, and in its place we find only anastamosing canals which 



