348 INTRODUCTION TO ZOOLOGY. 



barley the last season. " On this," says he, " in furtherance of 

 my favourite axiom, that every wild animal is of some service 

 to us, I determined to shoot some of the Wood-pigeons, that I 

 might see what they actually were feeding on ; for I did not 

 at all fall into my friend's idea that they were grazing on his 

 clover." Eight were accordingly shot as they flew over his 

 head. On being opened, "every Pigeon's crop was as full as 

 it could possibly be of the seeds of two of the worst weeds in 

 the country, the wild mustard and the ragweed, which they 

 had found remaining on the surface of the ground, these plants 

 ripening and dropping their seeds before the corn is cut. Now, 

 no amount of human labour and search could have collected, 

 on the same ground, at that time of the year, as much of these 

 seeds as was consumed by each of these five or six hundi*ed 

 Wood-pigeons daily, for two or three weeks together."* 



The Rock-dove (C. livia) builds in rocky chffs and caverns, 

 most usually in the vicinity of the sea, but occasionally inland. 

 It is the species from which the varieties of the domestic 

 Pigeon are derived. We cannot here detail the means by 

 which these are preserved and perpetuated ; we prefer limit- 

 ing our brief notice to one of these varieties, the Carrier- 

 pigeon, a bird whose services have been made available not in 

 love affairs only, but in those of the turf, the mart, the ex- 

 change, and the cabinet ; in all the deep stakes which are won 

 and lost in the chequered pursuits of human life. 



From the rapidity and general certainty with which the letter 

 entrusted to the Carrier-pigeon is conveyed, it would seem at 

 first sight as though the bird were guided by some mysterious 

 instinct ; but our wonder is diminished when we are aware of 

 the care and pains bestowed upon the training of these Pigeons. 

 They soon learn, in their daily excursions with the old birds, 

 to know their own abode, and to distinguish it from all others. 

 They are then brought a short distance from home in a covered 

 basket, and let loose. The distance is increased, until two, 

 four, eight, ten, or twenty miles are gradually attained ; and 

 this is continued until the entire distance they are expected to 

 perform has become familiar to them. When first let loose, 

 the flight is spiral ; when a sufficient elevation has been gained, 

 and some well-known object descried, the bird goes ofl' in a 

 direct and unwavering hne of flight. 



* Wild SporU of the Highlands, p, 119. 



