SHARKS AND RAY-FISHES. 
3 
impressed with the idea that the structure of the whole of them 
is greatly inferior as compared with the more firm and intricate 
structure of those which are termed bony fishes. We adopt 
the energetic language of Mr. Owen on this subject, and remark; 
“We should lose some most valuable fruits of anatomical study 
were we to limit the application of its facts to the elucidation 
of the unity of the vertebrate t3rpe of organization, or if we were 
to rest satisfied with the detection of the analogies between the 
embryos of higher and the adults of lower species in the scale 
of being. We must go further and in a different direction to 
gain a view of the beautiful physiological principle of the relation 
of each adaptation to its appropriate function, and if we would 
avoid the danger of attributing to inadequate hypothetical secon- 
daiy causes the manifestations of design, of supreme wisdom and 
beneficence, which the various forms of the animal creation 
offer to our contemplation. To revert then to the skeleton of 
fishes with a view to the teleological application of the facts — 
or that which regards them as means directed to an end — 
detei mined by the study of this complex modification of the 
anirnal framework. No doubt there is analogy betvmen the 
cartilaginous state of the endo-skeleton of Cuvier s chondrop- 
teiygiaus, and that of the same part in the embryos of the air- 
breathing vertebrates; but why the gristly skeleton should be, 
as it commonly has been pronounced to be, absolutely inferior 
to t e bony one is not so obvious. I know not why a flexible 
vascular animal substance should be supposed to be raised in 
“gical scale because it has become impregnated by 
the abundant intussusception of earthy salts.” 
active and vigorous of 
shes, like the birds of prey they soar, as it were, in the upper 
regions of their atmosphere, and without any aid from a modified 
respiratory apparatus, devoid of an air-bladder, they habitually 
maintain themselves near the surface of the sea hy the actions 
of their large and muscular fins. The gristly skeleton is in 
prospective harmony with this mode and sphere of life and 
we find well-marked modifications of the digestive and other 
systems of the Shark by which the body is rendered as Hght 
and the space which encroaches on the muscular system as 
small, as might be compatible with those actions. Besides, 
lightness, toughness, and elastieity are the qualities of the 
