ACEPHALOUS MOLLUSCA. 317 



that testaceous molluscs are animals with whom ossification is thrown 

 out on the external surface in place of the interior, as in the Mam- 

 mals, birds, reptiles, and fishes. In the case of the superior animals 

 the hones lie in the depths of the body ; in the shelled Mollusca the 

 bones are placed on the superficies. It is the same system reversed." 



Other zoologists reject as altogether untenable this assimilative 

 theory. " The shell which serves as a dwelling and a shelter cannot," 

 say these authors, " be considered as a skeleton, because it does not 

 assume the external form of the animal ; because it does not attach 

 itself to the organs of locomotion ; and, finally, because it is the pro- 

 duct of secretion, which increases in proportion to the development 

 of the body itself." This last opinion appears to us to be the most 

 acceptable. 



However that may be, from the immense variety of form and size, 

 from the beauty and brilliancy of their colours, the shells of the mol- 

 luscs are among the most attractive objects of natural history. Nor 

 is it from their beauty alone that a fine collection of -shells becomes 

 interesting : a living creature has inhabited the shell, a creature which 

 in its organization and its life, above all, by its habits, excites in a high 

 degree our interest, curiosity, and admiration. It has been said that 

 the shell " is like a medal struck by the hand of Nature to commemo- 

 rate climates." In short, the waters of different regions of the globe, 

 whether fresh or salt, are characterized by the presence of particular 

 shells ; moreover, the comparison of living shells with those which lie 

 in a fossilized state buried in the depths of the soil is a most important 

 element of our knowledge touching the origin of the different beds out 

 of which our globe is constituted. 



Thus, we must not shut our eyes to these beings, in appearance so 

 miserable and obscure, if we would possess a general knowledge of the 

 animal kingdom. The Creator has endowed them with many won- 

 derful gifts to embellish their lives, and who would dare to disregard 

 them ? Who could examine and compare their structure without being 

 charmed with the study ? Man, who descends into the depths of the 

 earth in search of the precious metals who dives into the deep in 

 pursuit of the treasures it conceals who stoops his head over works of 

 art would surely not refuse to bend himself for a moment to the 

 sand of the sea, to gather in his hand, to bring nearer to his eyes, 

 these marvellous works of the Divine Creator ! 



