CHARACTERISTICS OF THE SHARK. 309 



natives venture into the water, they resort to the aid of 

 a shark-charmer, whose exorcism is supposed to be an 

 effectual protection.* 



But we must now say a few words on the general char- 

 acter and organization of the sharks. 



As Professor Owen says,t not only are they the most 

 voracious, but they are the most active and vigorous of 

 fishes. Like the birds of prey, they soar, as it were, in 

 the upper regions of their atmosphere, and without any 

 assistance from a modified respiratory apparatus, and 

 though devoid of an air-bladder, they contrive to main- 

 tain themselves near the surface of the sea solely by the 

 action of their large muscular fins. 



With this mode and sphere of life, to adapt still further 

 the language of our great British naturalist, the gristly 

 skeleton admirably harmonizes ; and we can trace well- 

 defined modifications of the digestive and other systems 

 of the shark by which its body is rendered as light, and 

 the space encroaching on the muscular system as small, 

 as might be compatible with those actions. Moreover, 

 lightness, toughness, and elasticity are the qualities of the 

 skeleton most essential to the shark ; to yield to the con- 

 traction of the lateral inflectors and aid in the recoil are 

 the functions which the spine has mainly to perform in 

 the act of locomotion, and to these functions its alter- 

 nating elastic balls of fluid, and semi-ossified biconcave 

 vertebrae, most admirably adapt it. Had its entire skele- 

 ton been consolidated and loaded with earthy matter, the 

 consequent burden would have been wholly at variance 



* Sir Emerson Tennent, "Natural History of Ceylon," p. 578. 

 t Professor Owen, "Hunterian Lectures," vol. ii., lecture 6. 



