CH. XXX. PIGEONS DOVES. 159 



It must require no little labour to enable them to 

 fill their crops with this small seed. As in this 

 country the turnip-fields are for the most part 

 drilled and rolled, the poor birds have the greater 

 difficulty in satisfying the hunger of their young 

 ones ; and no young bird requires so much food 

 as an unfledged pigeon, in proportion to its size 

 and weight. 



The power of the pigeon to alter the focal length 

 of its eye must be very great, as it is able to see 

 equally well an object at a distance of many miles 

 and a minute seed not more than half an inch 

 from the end of its bill. 



The turtle-dove is sometimes, but only rarely, 

 met with as far north as Morayshire, but the 

 stock-dove is never seen in that part of the 

 country : if once introduced, I should imagine 

 that it would thrive perfectly well, as both the 

 climate and the natural productions of the district 

 are suited to it. 



The hardy little blue-rock pigeon abounds on 

 all the sea-coast of Scotland, where the rocks are 

 steep and broken into fissures and caverns one 

 moment dashing into its breeding-place, and rapidly 

 flying out the next ; then, skimming the very sur- 

 face of the breakers, this little bird gives animation 

 and interest to many a desolate and rugged range 



