OF VITAL ENERGY. 579 



we shall find that their powers of digestion, cir- 

 culation, sanguification, secretion, nutrition, and 

 muscular motion, are exceedingly low, that the 

 lungs, heart, stomach, brain, muscles, and other 

 organs, are imperfectly developed, compared with 

 the whale, dolphin, porpoise, and other cetacea, 

 which have large lungs, abundance of rich arte- 

 rial blood, and, like all warm blooded animals, a 

 highly organized stomach, heart, brain, and mus- 

 cular system. The truth is, that scarcely any 

 part of reptiles is more than half formed ; while 

 some of their organs may be said to exist in a 

 merely rudimentary state. Corresponding with 

 the obtuseness of their senses, and the low grade 

 of their intelligence, it has been observed by na- 

 turalists, that the brain of a crocodile twelve feet 

 long, and of a serpent eighteen feet long, does not 

 exceed from 1 to 2 drams in weight. 



If we descend the scale of organization from 

 reptiles to fishes, Crustacea, mollusca, and other 

 animals which breathe with gills instead of lungs, 

 and live constantly in water, which contains only 

 about 1 per cent, of free oxygen by volume, we 

 find, that although formed of the same elements, 

 animated by the same principle, and constructed 

 after the same model, as the highest species, they 

 resemble abortions compared with the finished 

 beauty of form exhibited in birds and mammalia. 

 For example, the heart of fishes is exceedingly 

 small, its walls thin, its pulsations slow and Ian- 



