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CLASS III. 

 A V E S. B I R D S. 



" Birds, the free tenants of land, air, and ocean 

 Their forms all symmetry, their motions grace." 



JAMES MONTGOMERY. 



WE have arrived at a new region, of a character altogether 

 different from any that we have hitherto traversed. At other 

 times, on crossing the line of boundary, we found the aspect 

 of the country unchanged, and the inhabitants nearest to the 

 frontier so like those from whom we had just parted, that at 

 first sight they seemed members of the same fraternity. But 

 such is not the case here ; the cold-blooded reptiles can never 

 be mistaken for the warm-blooded birds. We have reached 

 a new land: we have come among a strange people. Let us 

 observe their ways, and ask how they have been described 

 by those who have made them an especial object of study. 



Birds are oviparous animals; in other words, they are pro- 

 duced from eggs. They breathe by lungs, have warm blood, 

 and a heart with four cavities namely, two auricles and two 

 ventricles. The body is covered with feathers, and is fur- 

 nished with two wings and two feet. 



Connected with this higher organization, we see in birds the 

 power of flight in its fullest development. This alone would 

 separate them from any other class of vertebrate animals. It 

 is displayed in their long migrations, in the rapidity of their 

 course, and in the force with which the Eagle, " towering in 

 his pride of place," swoops upon his quarry. 



This power of flight is, of itself, a singular and interesting 

 subject, connected with the feathered tribes. It is one of 

 those wonders which may be viewed every day, would we but 

 open our eyes to see and our minds to consider them. 



Let us, for a few moments, endeavour to divest ourselves 

 of our familiarity with the phenomenon. "Let us," to use 

 the words of the Bishop of Norwich,* ' suppose a person to 

 * Familiar History of Birds, vol. i. Introduction, p. 3. 



