CHARACTERS OF THE MOLLUSCA. 5 



than anothei* ; certainly the mollusca arc not tlie least so, for 

 their numbers in species and individuals are proof of a propor- 

 tionate influence in the animal kingdom ; * their complexity of 

 organisation claims for them a considerable rank in its roll; and 

 the many notable peculiarities of structure in their nervous 

 system, in their circulatory apparatus, in their secretions, and 

 in their generative system, recommend them in a lively manner 

 to the comparative anatomist and physiologist. It was in 

 such investigations that Cuvier laid the foundation of his 

 immortal fame ; and the results of them he has recorded in 

 a work which has become one of the Conchologist's most 

 valued classics. I mention it now as a proof that you have 

 engaged in no worthless or trifling pursuit, and a stronger one 

 I cannot give ; for, after Cuvier had attained a reputation 

 surpassed by no cotemporary philosopher, he thus speaks of 

 his first studies, and thus invites you to their participation : 

 if, says he, in allusion to the work just mentioned, " these 

 Memoires have no other effect than to direct the attention of 

 others to the singular peculiarities which the history of mol- 

 luscous animals offers to their notice, I shall have done well, 

 and be repaid for the toil of my task ! " We honour ourselves 

 in accepting the invitation of such a man. 



It was Cuvier who, first of all, gathered together these 

 animals, hitherto scattered among many classes, and assigned 

 to the group or subkingdom the denomination of Mollusca, 

 a term in previous use, but which had been very vaguely 

 defined and applied. They are so named because they have 

 soft fleshy bodies, devoid of bones. They are readily distin- 

 guished from all above them in the animal kingdom by the 

 want of an interior skeleton, and by the colourless condition 

 of their blood ; and from insects and worms they arc distin- 

 guished with equal facihty, for the body of the Mollusca is 

 never divided, like that of insects and worms, into rings, nor 

 invested with a hard crust or skin, fitted like a coat of mail, 

 to the junctures, nor even furnished with jointed limbs and 

 organs of progression. On the contrary, the Mollusca have a 

 soft undivided body, covered with an irritable mucous skin, 

 moistened with a \dscous liquor, which exudes from it : this 

 skin, in very many instances, is ample enough to be formed 

 into membranes and fleshy folds, and hence assumes somewhat 



, * "The number of Mollusks already in collections, probably reaches 

 8,000 or 10,000. There are collections of marine shells, bivalve and uni- 

 valve, which amount to 5,000 or (5,000 ; and collections of laud and Huviatile 

 sliclls, which count as many as 2,000. The total number of Mollusks avouKI 

 tlierefore probably exceed 15,000 species." — Agassiz and Gould's Princ. of 

 Zoology, i. p. 3. 1848. 



