118 THE CONE AND OLIVE SHELL. 



the coral to which it is attached, until the original shell 

 is quite buried in this vitreous substance. 



The forms of the cone, fig. 1, and olive shell, fig. 2, 

 are such as to allow but a small space for the convolu- 

 tions of the body of the animal, which consequently 



Fig. 1. Fig. 2. 



becomes exceedingly cramped in the progress of its 

 enlargement. What then would be the expedient of 

 human wisdom ? One, doubtless, infinitely inferior to 

 that adopted. In order to obtain more space, and, at 

 the same time, to lighten the shell, the whole of the 

 two outer layers of the inner whorls of the shell are 

 removed, leaving only the interior layer^ which is there- 

 fore very thin when compared with the other whorl, 



