Till IXTKODUCTION. 



insensibly with tlie calcareous exudation already noticed, and thus 

 Oi-casions that exquisite variety in their testaceous coverings, -which 

 art attempts to emulate, but can never fully equal. Thus far is 

 the result of observation and experiment. It iio\v remains to 

 account for the extraordinary fact that the stony exudations of 

 testaceous animals condense only on those parts where they are 

 essential to their welfare. But here investigation ends — the micro- 

 scope has done its of^ce. It seems as if material nature delighted 

 to baffle the wisdom of her sons, and to say to the proud assert ors 

 of the sufficiency of human reason for comprehending the mysteries 

 of creation and of Providence, 'Thus far can you go, and no 

 farther; even in the formation of a shell, or its insignificant 

 inhabitant, your arrogant pretensions are completely humbled.' " 



USES OF SHELLS. 



In speaking of shells as oniaments, and objects worthy of our 

 study and admiration, we have already mentioned some of their 

 uses, for surely that which contributes to the intellectual improve- 

 ment and innocent pleasui'e of mankind, is in its degree useful. 

 But on the more narrow ground of utility, shells may also claim 

 a high place in our estimation. To man in a barbarous and 

 luicivilized state, they furnish the means of performing some of 

 the most important operations of daily life, being extensively used 

 as a substitute for iron. The savage frequently forms his knife, 

 his hunting spear, and his fish-hook of hard shell. Lister relates 

 that the inhabitants of I^icaragua, in South America, fasten a 

 shell, called the Osirea virgir.ica, to a handle of wood, and use 

 it as a spade. In North America the natives use a blue and 

 white belt composed of shells called the I'enus mercenan'a, as a 

 symbol of peace and unity, and there too the gorget of the 

 chieftain's war-dress is composed of the pearl-bearing mussel, called 

 by naturahsts Mi/tilns minyaritift'rus. Many African tribes use 

 the jdurex tritonis as a mihtary horn, and a rare variety of this 

 shell, which has the volutions reversed, is held sacred, and used 

 only by the priests. Among the Friendly Islanders the Orange 

 Cowry is a S}Tubol of the highest dignity. The Money Cowry, 

 (Ci/prcea monetaj fomis the current coin of many nations of 

 Africa; and a certain number of these shells strung together, are 

 considered by the slave-hunting chiefs, as an equivalent for so 

 many black-skinned brothers, whom they sell into hopeless bondage. 



Among nations, too, in a high state of civilization, shells are 

 often used for economical as well as ornamental purposes. To 

 say nothing of mother-of-pearl, which is converted into so many 

 articles useful as weU as pretty, scallop, or oyster shells, are fre^ 



