SHELLS AND MOLLUSCOUS ANIMALS. 177 



large enough to serve as food for man. The 

 ancients regarded them as forming a dish for an 

 epicure; and in the present day one species is 

 cooked and eaten by the Chinese, and said to 

 resemble the lobster in flavour. 



Sometimes when wandering along the shore, or 

 stooping among the rocks to pick up the treasures 

 which the naturalist finds hidden there, we alight 

 upon, some stray piece of drift-wood. It may be 

 but a part of a tree borne down long ago by a 

 river to the spot, or it may be a piece of wood 

 stranded from some wreck, awakening thoughts of 

 pity as we look upon it, reminding us of 



" Shipwrecks and their spoils, 

 The wealth of merchants, the artillery 

 Of war, the chains of captives, and the gems 

 That glow'd upon the brow of beauty ; crowns 

 Of monarchs, swcrJs of heroes, anchors lost 

 That never had let go their hold in storms ; 

 Helms sunk in ports, that steer'd adventurous barks 

 Round the wide world." 



But our piecs of drift-wood acquires another source 

 of interest if ii; be covered, as it sometimes is, with 

 the stalked, or duck barnacle (Pentelasmis anati- 

 fera). Sometimes thousands of these creatures 

 are crowded on a piece of wood but a few feet 

 long, all twisting about, and presenting a moving 

 mass of life, almost disgusting to any but the 

 accustomed eye of the naturalist, who knows that 

 among this mass he may find curious shells, coral- 

 lines, and other objects which are not scattered on 

 the shore. The growth of these animals must be 

 very rapid, as the keel of a ship which has made 

 but a short voyage will be sometimes entirely 

 covered with them ; and in some cases they are so 

 numerous as even to impede the course of a vessel* 



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