Uses of the Crossbill to a Cone-feeding Bird, i6g 



case of the incisor teeth of rodents might be quoted, where the 

 plane of contact between the upper and lower is deflected, so 

 that the teeth, growing, as they do, by additions from behind, 

 often protrude, and grow upwards or downwards, as the case 

 may be, to an indefinite extent, and often cause the death of 

 the animal by starvation. In the case of a bird, we may sup- 

 pose a similar accident occurring in a young individual, the 

 bill of which happens not to be so 'stout as usual, and from 

 some twist in digging has been displaced, so that the tips are 

 not in apposition, and would accordingly go on growing in 

 the same way until the deformity, as above, resulted. Now, 

 although to a granivorous animal such a condition would be 

 decidedly injurious, in the case of the conical-shaped bill of the 

 cone-feeding crossbill, the sharp cutting and falcated edges 

 would be just the opposite, for they would scoop out the seed 

 of a cone more effectually than a slender straight beak, from 

 which we might conclude, on the principle of natural selec- 

 tion, that no better accident could have occurred to the finch, 

 and scarcely a worse one to the crow, who subsists more or 

 less by picking up substances on the surface. % 



The crossbill makes use of the hooks to assist it in moving 

 along the sides of the cage, where it crawls like a parrot ; it has 

 also another similar habit, that of picking up cones with its feet 

 and carrying them to a branch, where, hawk-like, it holds them 

 in its talons and dissects them from top to bottom. Never- 

 theless, in winter, all the pine-feeding birds seem willingly to 

 abandon their fir-cones for the refuse of the lumber camp or 

 the dunghill, and the buds of early spring. 



At the end of March, when the sunny days invite us forth, 

 flocks of crossbills, redpolls, and pine siskins may be seen on 

 the firs, spruces, and larch trees, singing sweetly, whilst the 

 females and young of the year are feeding on the cones. 

 Shortly afterwards the males disappear, and throughout the 

 summer we only meet with small flocks, which would lead to 

 the belief that the majority go to more northern regions. 



