204 MULI.l'SKS. 



draws itself wholly within the same again. Mollusks 

 have, in a greater or less degree, the senses of the 

 higher animals, though they greatly differ among 

 themselves in this respect. 



The kinds of Mollusks are very numerous, — not less 

 than fifteen or twenty thousand. They abound in 

 the sea, on the marshes, in pools, streams, ponds, and 

 lakes, and on the land ; and they are full of interest 

 when we study them, and all ser\'e some important 

 purpose. The^' are the food of many other animals. 

 The Right Whale feeds upon small kinds which swim 

 freely in the open sea ; the Cod and Haddock and 

 many other useful fishes fatten upon those gathered 

 near or on the bottom ; and sea birds feast upon 

 those left bare b\' the tide. Man reckons the Oyster, 

 Clam, and Scallop among his choicest dishes ; and in 

 seasons of scarcity the poor inhabitants on many a 

 seacoast depend upon Mollusks for a large part of their 

 daily food. These animals also furnish the bait for all 

 the extensive fisheries of the north Atlantic. Some 

 of them yield rich dyes. The celebrated T^'rian pur- 

 ple of the ancients was obtained from sea snails. 



The shells of Mollusks are of limestone, or carbonate 

 of lime. Pearly ^^•ithin, and of soft and delicate colors, 

 they are often exceedingly beautiful, and are eagerly 

 sought for. The child gathers them for toys, and 

 thinks he hears the roaring of the sea as he puts them 

 to his ear; the savage wears them as ornaments, and 

 some of them as marks of chieftainship ; some kinds 

 are gathered by civilized nations and used instead of 

 money in trading ^\•ith barbarous tribes ; other kinds 

 are gathered and wrought by skillful hands into almost 

 numberless articles of use and luxury ; and the true 



