1 68 Field and Forest Rambles. 



palmatus), besides the webbing of the feet, by which it is 

 alone distinguished "from E. hiaticida, and thus interesting 

 from being an adjunct to the bird in the way of swimming as 

 well as wading, has also been probably acquired through 

 natural selection. Now this species has likewise a very wide 

 distribution, and is very abundant, and, according to the 

 excellent authority just quoted* there is much discrepancy 

 in the length of bills in individuals, even to the extent that 

 the student, meeting only with the two extremes, would 

 deem it impossible that they should be specifically identical. 

 I might cite numerous other pertinent examples — to wit, the 

 Little Willet (T.Wilsonii), the Red-backed Sandpiper, 

 etc., etc. But to return to the crossbills. We frequently 

 meet with analogous deformities in other birds — for example, 

 the rook and the carrion crow seem especially subject to such 

 states. In one instance I found the mandibles more slender 

 than is natural ; and probably this defect was the cause of the 

 distortion, which was evidently a serious incumbrance to the 

 bird when feeding; for whereas the usual length of the bill is two 

 inches and a half, in the above the upper mandible was three 

 inches and a half along the curve, and the lower four inches. It 

 is clear, therefore, that this conformation entirely precluded the 

 possibility of the individual obtaining subsistence in the usual 

 manner ; it must have, therefore, used the upper blade like a 

 pickaxe ; but the bristles on the nostrils and base of the bill 

 were extensively denuded, like that of old rooks, as has been 

 alleged by inserting the bill deep in soil, which must have 

 been next to an impossibility in this case. Therefore, unless 

 the denudation took place prior to the deformity, it is utterly 

 impossible that it could have occurred afterwards. 



The point, however, we are most concerned about at present 



is the attempt to interpret the probable cause of the deformity, 



having seen the disadvantage it would be to the bird in its 



struggle for existence. Among quadrupeds the well-known 



* Op. cit, p. 725. 



