GROWTH AND HABITATION. 15 



touchy does not assume the narrow cylindrical BuUa-ioYTa, 

 nor yet revolve around a columella axis ; it takes the wide 

 ventricose shape of a Cp?iba, and rapidly consolidates into 

 the adult shell. It is therefore evident that the CyprcBa 

 removes at will any portion that impedes his full develop- 

 ment ; that when his house becomes too small for his com- 

 fortable occupation he causes it to melt away as by the 

 touch of an enchanter^s wand ; and lastly, that he reconstructs 

 with equal facility the beauteous edifice that constitutes his 

 home. The operation is, however, said to be of rare occur- 

 rence, and to happen only under peculiar circumstances. 



Yet not less wonderful is the gradual increase and 

 development of shelly structures, with gradations of form 

 and hue, and architectural embellishments which occur at 

 different periods. It even seems as if the animal inhabitant 

 in progressing from youth to fuU maturity, acquired new 

 ideas with skill to embody them ; and so great a difference 

 subsists between the extremes of age, that shells of young 

 Cowries were figured by our forefathers as Bidlce. Adanson 

 collected them in a separate genus, with the title of Peribo- 

 his ; and a celebrated continental naturalist of the present 

 day was long unable to abandon this chimera. The changes, 

 therefore, among Cowries, both of colour and of pattern, with 



