MIGRATIONS. 103 



and both return from whence they came, when 

 the errand of their voyage is fully accomplished. 

 One sent away by too great heat, and the other 

 by a gradual decreement of the amount of heat, 

 and also of their customary food. 



Vieillot says, that all the swallows do not quit 

 the warm countries to which they betake them- 

 selves in winter that one part migrates, while 

 another remains stationary, during the whole 

 year, in Egypt, Ethiopia, and other tropical 

 countries and islands. 



But, besides the insectivorous emigrators>many 

 of the higher and more powerful tribes are ac- 

 customed to change one country for another. 

 When the carcasses of animals putrify, and birds 

 multiply under the influence of the northern 

 sun, vultures, eagles, falcons, hawks, &c. leave 

 the south and go to partake of the feasts pro- 

 vided for them in higher latitudes. 



But, besides the birds that visit us during the 

 more genial part of the year, and add so greatly 

 to the beauty and music of our groves in spring 

 and summer, there are others, and those a 

 numerous tribe, that wing hither their way when 

 the reign of winter has commenced. The most 

 numerous of these are the birds which the 

 Author of nature has fitted to disport themselves 

 and seek their food in the water, or which fre- 

 quent humid and watery places. When the 

 Arctic seas, and lakes, and rivers, present an 



