THE COMMON CROSSBILL. 231 



themselves across the cone, then bring the points of the 

 mandibles from their crossed or lateral position, to be im- 

 mediately over each other. In this reduced compass they 

 insinuate their beaks between the scales, and then, opening 

 them not in the usual manner, but by drawing the 

 inferior mandible sideways force open the scales." " At 

 this stage," Yarrell proceeds to say, " the end of the tongue 

 becomes necessary ; and this organ is no less admirably 

 adapted for the service required. . . . While the points of 

 the beak press the scale from the body of the cone, the 

 tongue is enabled to direct and insert its cutting scoop 

 underneath the seed, and the food thus dislodged is trans- 

 ferred to the mouth; and when the mandibles are separated 

 laterally in this operation, the bird has an uninterrupted 

 view of the seed in the cavity with the eye on that side to 

 which the under mandible is curved." 



The beak of the Crossbill then, far from being a defect 

 in the organization of the bird, is a perfect implement 

 always at its owner's command, faultless alike in design 

 and execution, and exquisitely adapted to its work, not 

 an easy one, of performing, by a single process, the office 

 of splitting, opening, and securing the contents of a fir- 

 cone, and he must be a bold man who could venture to 

 suggest an improvement in its mechanism. 



It has been observed that young birds in the nest have 

 not their mandibles crossed, and at this period such an 

 arrangement would be useless, as they are dependent for 

 food on the parent birds. It has also been observed that 

 the side on which the upper mandible crosses the lower 

 varies in different individuals ; in some it descends on the 

 right side of the lower mandible, in others on the left. 

 The bird appears to have no choice in the matter, but what- 

 ever direction it takes at first, the same it always retains. 



The Crossbill is not believed to be generally a continuous 

 resident in this country, though several instances are on 

 record of its breeding with us. From the fact, too, that 



