MIGRA TION A ND FL IGHT. 83 



but if called by any of the servants, whose voice it knew, 

 would return, and feed out of their hand. For a day or two, 

 towards the close of summer, it seemed rather uneasy, getting 

 into the coal-hole and cellar ; but this soon wore off. As the 

 evenings got cool, in the autumn, it returned again to its cage 

 before nightfall, and was taken as usual into the house. As 

 the season still further advanced, it was to be permanently 

 housed, and was expected to sing again at Christmas. 



Other facts deserve attention, proving that mere climate is 

 by no means, in all cases, the cause of these periodical visits. 

 Thus some birds will, on the introduction of a new system of 

 cultivation, make their appearance in countries where they 

 were never seen before. The Crossbill has followed the apple 

 to England. Glencoe, in the Highlands of Scotland, never saw 

 the Partridge till its farmers introduced corn into their lands. 

 The Sparrow again ex- 

 tended its range with 

 the tillage of the soil. 

 Thus, during the last 

 century it has spread 

 gradually over Asiatic 

 Russia, towards the 

 north and east, always 

 following the progress 

 of cultivation. It made 

 its first appearance on Crossbill, 



the Irtisch, in Tobolsk, soon after the Russians had ploughed 

 the land. It came, in 1735, up the Obi to Berezov, and four 

 years afterwards to Naryn, about fifteen degrees of longitude 

 farther east. In 1710, it had been seen in the higher parts of 

 the course of the Lena, in the government of Irkutzk. In all 

 these places it is now common, but it is not yet found in the 

 uncultivated regions of Kamtschatka.* From certain entries 

 in the Hunstanton Household Book, from 1519 to 1578, in 

 which Sparrows (or, as they are there written, Spows, or 

 Sparrhouse) are frequently recorded, it would appear that 

 * LYELL'S GeoL, iii. 22. 



