390 VERTEBRATED ANIMALS. 



careful and long- continued observations of Mr. Thompson 

 and Mr. E. C. Couch. 



A wide line of demarcation marks the separation of 

 the invertebrata from the four great classes of vertebrate 

 animals fishes, reptiles, birds, and mammalia. Every 

 part of the globe, the ocean and the inland lake, the 

 wide and far-winding river, and the babbling stream, 

 the mountain and the valley, the forest with its depth 

 of shade, and the desert with its intensity of light, 

 the cold regions of the frost-chained north, and the 

 fervid clime within the tropics presents for our study 

 innumerable animals, each fitted for the conditions to 

 which it is destined ; and through the whole we find a 

 gradual elevation in the scale of intelligence, until at 

 last, separated from all by peculiar powers, we arrive at 

 man himself. 



In each of these four classes the animals are fur- 

 nished with a bony skeleton, which is in the young 

 animal little more than cartilage; but, as growth in- 

 creases, lime becomes deposited, and a sufficient degree 

 of hardness is thus produced to support the adult for- 

 mation. Some anatomists have endeavoured to show 

 that even in the mechanical structure of the bony fabrics 

 of animals, we are enabled to trace a gradual increase 

 in the perfection of arrangement, from the fish until the 

 most perfect is found in man. Many of the mammalia, 

 however, are furnished with skeletons which really 

 surpass that of man. These belong to animals which 

 depend for subsistence upon their muscular powers, and 

 with whom man is, in this particular, on no equality. 

 What is the lord of the creation, compared with the 

 antelope for fleetness, or with the elephant and many 

 other animals for strength ? 



As we ascend the scale of animal life we find a more 

 perfectly developed nervous system; and the relative 

 size of the brain, compared with that of the brute, is 

 found progressively to increase, until it arrives at the- 



