Causes of the strange Curving of Birds' 1 Beaks. 167 



winter. It is apparently also less carnivorous than the white- 

 winged crossbill ; whose sharp, narrow, and falcated bill is 

 better adapted for slipping between the imbricated scales of 

 the red spruce and other cones. I have repeatedly noticed 

 that they extract the seed by a twist, like a dentist extracting 

 a molar, just in such a way as to cause the forceps to cross 

 its blades. Now as the young have the mandibles even, and 

 as the direction of the tips in the old birds is sometimes to 

 the right and sometimes to the left, one might speculate 

 on a far-back time when some progenitor discovered, in its 

 struggle for existence in the pine forest in winter, that the 

 seeds of the cones were to be got at, and when in its attempts 

 to get at them the bill, which is not so strong and conical 

 as that of the pine bullfinch, became curved, until at length 

 the condition became hereditary and transmissible. Indeed, 

 this hypothetical mode of reasoning does not stop at the 

 crossbills ; for, looking to the digging habits of, for example, 

 the curlew and ibis, and the dredging way of feeding of the 

 flamingo, the poking under stones of the avoset, godwit, and 

 numerous other birds with bent and distorted bills of slender 

 make, we might with as much plausibility attribute the present 

 outline of the bill in them to habits long practised. 



Looking at a few pointed instances in connection with the 

 birds of this province, I might cite the long-billed curlew, 

 common to the entire [temperate region of the Continent, 

 but here only an en passant visitor on its way north and south 

 at the usual times. This bird, and, I might add, its European 

 congener the slender-billed curlew, are subject to much 

 diversity in regard to the bill. As regards the former species, 

 Mr. Baird found* that scarcely two specimens shared the 

 same length and . dimensions of the bill. Another widely 

 distributed water bird, the sanderling, the habits and haunts 

 of which are well known, shows also much diversity in 

 size of body and length of bill. The ting plover {E. semi- 

 * Op. tit., p. 728. 



