HAWAIIA.\ BIRDS. 59 



doubt for a moment that the peculiar bill of Loxops has originated 

 in a similar way and has similar functions. 



In his "Further Remarks on the Relations of the Drepanididae" 

 in Wilsons' "The Birds of the Hawaiian Islands," Dr. Gadow 

 refers to this peculiarity as follows: "Curiously enough, there 

 exists another still more striking analogy between the crossbills 

 and some Hawaiian birds, iiamel)'- with Loxops incl. Chrysomi- 

 tridops. As already known to Cabanis, when he established the 

 genus Loxops, the under jaws of these little birds are not sym- 

 metrical — the distal half of the under jaw is twisted either to the 

 right or to the left. It is interesting to note that the amount of 

 twisting varies individually, right- and left-billed specimens occur- 

 ring in equal numbers, and that it is smallest in young birds. 

 There is not the slightest doubt that this asymmetry is acquired 

 individually by their twisting open husks and seeds, or cracks of 

 bark, in search of their food." 



Notwithstanding the indicated function of the bill of Loxops 

 and the apparent relation of cause and effect observable in its 

 shape, the writer is bound to state that nothing in the habits, of 

 the bird, so far as he has been able to observe them, lends anjs 

 color whatever to the theory; nor can he learn that Perkins' ex- 

 perience was different. As stated above Loxops hunts its prey 

 among the leaves, the small, outermost twigs, and the flowers of 

 the koa, but never, so far as the writer is aware, probes into the 

 cracks and crevices of the bark for food nor twists off "husks and 

 seed." The bird may, indeed, possess these latter habits, as its 

 bill indicates it should, but none of the thirty or forty individuals 

 the writer has seen have thus been employed, nor do the contents 

 of the many stomachs he has examined contradict his observa- 

 tions. 



Moreover, the peculiar twist of the bill does not seem to be in 

 any wise dependent on age but, on the contrary, is as apparent in 

 some ten or fifteen individuals in juvenile plumage as it is in the 

 oldest individtials. Individually, however, the birds differ much in 

 the extent to which the bill is twisted. 



The writer can but regret that he has no theory of his own to 

 propose in place of the one above given which, however sound and 



