ORDER PASSERES. 83 



the insect tribes, particularly those in the winged state, 

 which they pursue with unabated vigour and success. This 

 pursuit is either close along the surface of the ground, or 

 more or less elevated above it, according to the state of the 

 atmosphere, which seems to govern the elevation of flight of 

 insects. The relative state of humidity in the air may thus 

 be inferred from the elevation of the swallow's flight, while 

 the vulgar regard it as actually anticipating the weather. 



That swallows are serviceable to mankind, by the destruc- 

 tion of hosts of insects, injurious to our industry and con- 

 venience, cannot be doubted; but there is certainly more of 

 enthusiasm than of sound philosophy in asserting, that this 

 was the object of their creation ; and there is perhaps too 

 great a proneness in many well meaning persons, of warm 

 imaginations, to conclude, that man is as it were the sole 

 object of creation, and that every thing beneath him is 

 wholly subservient to his existence. Man has indeed enough 

 to be grateful for without derogating from the value of in- 

 ferior creatures, or conclviding that one set of beings was 

 created solely for the destruction of another, that the balance 

 of power might be thus preserved exclusively for his con- 

 venience. That this balance of power is a subject of the 

 greatest admiration is perfectly true ; but that it is attributable 

 to a much higher and more direct agency than that alluded 

 to, is most probable. 



The emigration of birds is a subject so entirely indepen- 

 dent of all physical principles, as far at least as we can 

 discover, that it may, without any figure of speech, be 

 considered a standing miracle. We are generally ready 

 rather to run into absurdities in endeavouring to ac- 

 count for phenomena by material sensible agency, than to 

 admit that our own powers of intellect are too finite to coii- 

 conceive the modus operandi of Providence. 



Hence, with reference to the particular subject of the migra- 



g2 



