MATERIAL UNIVERSE. 75 



for which he was formed, still continues ; the 

 megatherium, mastodon, megalonyx, and many 

 others, whose remains have been preserved, and 

 their habits and forms indicated by the science 

 and ingenuity of man, then existed. 



These animals, and vegetables, could not have 

 attained their immense size, except under pecu- 

 liar circumstances, favorable to their growth ; 

 among which, evidently, the high uniform tem- 

 perature, and humidity of the earth, at that time, 

 stand conspicuous. These gradually gave place 

 to other species of animals and plants, of minor 

 proportions, when the reduced temperature of 

 the earth's surface no longer provided them with 

 sufficient warmth and sustenance. Then, every 

 thing was gigantic: but, as the waters cooled, 

 new organizations were effected, of less magni- 

 tude, but of more perfect development, in the 

 still fruitful waters. 



