234 FISHES. 



CHAPTER XXIII. 



FIRST CLASS OF VERTEBRATE ANIMALS. 

 FISHES. 



MORE than two-thirds of the surface of our globe is covered 

 by the sea : continents and islands are everywhere inter- 

 sected by rivers and overspread with lakes and ponds, thus pre- 

 senting an aggregate of waters so considerable as far to exceed 

 the dry land in extent, and affording space for the existence of 

 animated beings, by no means inferior, in number or variety of 

 species, to those which inhabit the earth. 



At first sight, we might suppose that the watery element 

 afforded little diversity, and that the various races of fishes 

 could as well inhabit one locality as another. The sea, however, 

 in different latitudes offers great differences of temperature, espe- 

 cially in the vicinity of coasts, some of which, exposed to the full 

 influence of a burning sun, reflect intolerable heat, whilst others, 

 covered with snow regions of ice and frost exhibit a perpetual 

 winter. Vast lakes are raised to considerable elevations, and 

 from their glacier-barred sides the rivers stream with icy coldness. 

 The rivers and the lakes are all fresh water, light and pure ; the 

 seas are salt, and thus of greater density ; some waters are clear 

 and limpid, others are agitated by continual currents, whirled in 

 cascades, or hurried on in ceaseless torrents : the crystal fountain, 

 and the muddy marsh, and all the shades of difference between 

 these extremes, present so many climates, all of which require 

 creatures of different habits and endowed with different faculties. 

 We need, therefore, be no longer astonished at the infinite variety 

 in the forms and endowments of the finny tribes, or surprised that 

 some of them are of shapes that to our ignorance appear mon- 

 strous and deformed, while others are very paragons of elegance 

 and beauty. Many fishes, indeed, are adorned by the hand of 

 Nature with every kind of embellishment variety in their forms, 

 elegance in their proportions, diversity and vivacity in their 

 colours ; nothing is wanting to attract the attention of mankind. 

 The splendour of every metal, the blaze of every gem, glitter 

 upon their surface ; iridescent colours, breaking and reflecting in 

 bands, in spots, in angles, or in undulating lines always regular or 

 symmetrical, graduating or contrasting with admirable effect and 

 harmony, flash over their sides : for whom have they received 



