88 BRITISH BIRDS. 



nature of the climate. I believe it extends to the southern extremity of 

 Fuegia, while northwards, if I am not mistaken, it ranges as far as Peru— 

 thus passing through every variety of chmate, from an intensely humid cold 

 region to a tropical one where rain hardly ever falls." It is remarkable that, 

 for certain purposes, Nature has instituted migration ; for another purpose, 

 as the converse, she has taken away flight. The loss of volant power is as if 

 a man tethered his cow in a clover-field ; he wishes it to stay there to keep 

 down the abundance in that spot ; the cow must not go away, but act on that 

 particular place with regularity. To prevent migration in a locality where the 

 bird is always wanted, volant power is absent. It was so with Aka impetmis, 

 which has been, as all flightless species will be, quite destroyed. OfApteryx and 

 Dinornis Sec. it is said that when they were segregated from others, they 

 lost the power of flight from disuse of their wings ; but if we contemplate 

 the Ostrich and different members of the family, there does not appear to be 

 much governing value in the argument. 



Mr. A. R. Wallace states, in the ' Malay Archipelago,' vol. ii. p. 66 : — 

 " From a small island a hundred miles north of New Guinea, a Nicobar Pigeon, 

 which must have come from New Guinea, fell into the water exhausted before 

 it could reach the shore." He proceeds to argue that it was safer for a 

 ground-feeding bird in New Zealand not to fly at all than to fly badly, because 

 of the distance of New Zealand from other land ; " while in a vast archipelago 

 strewn with islands, it was advantageous to be able occasionally to migrate ; 

 then the long and strong- winged varieties maintained their existence longest, 

 and ultimately supplanted all others." His argument gives safety to the birds 

 as a cause of volant and non-volant power. My idea is, natural location was 

 the cause, viz. the necessity for creatures to remain in allotted spots to carry 

 out the work required of them in the chain of life in those places. Safety to 

 the animal is always made, as I view things, subordinate to its use and duty, 

 though without doubt its safety has been guarded. I can understand the 

 theory that a bird in an oceanic island, far from other land, might, with no 

 enemies, cease to use its wings, being a ground- feeder, and thus at last lose 



