554 SWALLOWS. Class IL 



Prosper Alpinus* asserts the same; and Mr. 

 Loten, late governor of Ceylon, assured us that 

 those of Java never remove. These excepted, 

 every other known kind observe a periodical 

 migration, or retreat. The swallows of the cold 

 Norway,'\ and of North America,^ of the 

 distant Kamtschatka^, of the temperate parts 

 of Europe, of Aleppo,\\ and of the hot Jamaica,^ 

 all agree in this one point. 



In cold countries, a defect of insect food on 

 the approach of winter, is a sufficient reason 

 for these birds to quit them; but since the 

 same cause probably does not subsist in the 

 warm climates, recourse should be had to some 

 other reason for their vanishing. 



Of the three opinions, the first has the ut- 

 most appearance of probability ; Avhich is, that 

 they remove nearer the sun, Avhere they can 

 find a continuance of their natural diet, and a 

 temperature of air suiting their constitutions. 

 That this is the case with some species of Eu- 



* Hirundines duplicis generis ibi observantur ; patriae scili- 

 cet quae nunquam ab JEgypio discedentes, ibi perpetuo mo- 

 rantur, atque peregrinae, has sunt nostratibus oiiinino similes j 

 patriae vero toto etiam ventre nigricant. Hist. JEgi/pi. i. I98. 



t Pontop. hist. Norw. ii. 98. J Cat. Carol, i. 51. app. 8. 



§ Hist. Kamts. 162. \\ Russel Alep. 70. 



U Phil. Trans. No. 36. 



