364 INTRODUCTION TO ZOOLOGY. 



''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 heing opened, "every 

 Pigeon's crop was as full as it could possihly he 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 con- 

 sumed by each of these five or six hundred Wood-pigeons 

 daily, for two or three weeks together."* 



The Rock-dove ((7. livid) builds in rocky cliffs 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 limiting 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 exchange, 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 distin- 

 guish 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 off in a direct and 

 unwavering line of flight. 



* Wild Sports of the Highlands, p. 119. 



