BIRDS IN A VILLAGE 93 



action of birds for the preservation of the species, 

 that of migration, is undoubtedly the most dangerous 

 of all. It is so perfect that by means of this faculty 

 miUions and myriads of birds of an immense variety 

 of species, from cranes, swans, and geese down to 

 minute gold crests and firecrests and the smallest 

 feeble-winged leaf warblers, are able to inhabit 

 and to distribute themselves evenly over all the 

 temperate and cold regions of the earth, and even 

 nearer the pole : and in all these regions they rear 

 their young and spend several months each year, 

 where they would inevitably perish from cold and 

 lack of food if they stayed on to meet the winter. 

 We can best realize the perfection of this instinct 

 when we consider that all these migrants, including 

 the young which have never hitherto strayed beyond 

 the small area of their home where every tree and 

 bush and spring and rock is familiar to them, rush 

 suddenly away as if blown by a wind to unknown 

 lands and continents beyond the seas to a distance 

 of from a thousand to six or seven thousand miles ; 

 that after long months spent in those distant places, 

 which in turn have grown familiar to them, they 

 return again to their natal place, not in a direct but 

 ofttimes by a devious route, now north, now north- 

 east, now east or west, keeping to the least perilous 

 lines and crossing the seas where they are narrowest. 

 Thus, when the returning multitude recross the 



