in several Species of Birds. 4.03 
denuded state of the nostrils and the anterior part of the head, 
both of which are entirely destitute of feathers. ones 
specimen, in the possession of Mr. R. Wood, a zealous col- 
lector of objects in natural history, residing in Manchester, 
has the mandibles greatly elongated and much curved, as in 
the case of the jackdaw detailed above. Now it is cident that 
the bird, possessing a bill thus formed, could not thrust it into 
the ground in search of worms and the larvee of insects, as 
the rook is known to do habitually; and, accordingly, the 
plumage at the base of the bill of this individual, and the 
bristly feathers which cover its nostrils, are very conspicuous, 
not having sustained the slightest injury. The opinion enter- 
tained by many persons, that the naked condition of the nos- 
trils and anterior part of the head is an original peculiarity 
in the rook, is thus satisfactorily proved to be incorrect ; 
indeed, the fact that young rooks exhibit no deficiency in 
these particulars is sufficiently conclusive on this point: but 
the possibility of an entire species being endowed with an 
instinct destructive of a useful portion of its organisation, 
which, consequently, appears to be bestowed upon it in vain, 
was probably never contemplated by these observers ; it is 
not surprising, therefore, that the inference deduced from a 
partial view of the subject should be erroneous. 
‘The last instance of this anomalous structure of the bill 
which has fallen under my observation, occurred in a speci- 
men of the red-headed woodpecker (Picus erythrocéphalus), 
contained in a collection of birds’ skins lately brought from 
the United States of North America. In this individual the 
mandibles, though pretty much elongated, are but slightly 
curved, the upper one, as in the preceding cases (Mr. Wood’s 
rook AEG excepted, in which the direction is reversed), cross- 
ing the lower one on the right side. A bill so constructed 
must haye proved exceedingly inconvenient to a bird of this 
species. 
I might now proceed to speculate upon the circumstances 
which have contributed to produce this phenomenon ; but, as 
my acquaintance with the history of the birds in which I have 
seen it exhibited is so imperfect, that any thing I could 
advance concerning them would be little more than conjec- 
tural, I possess no certain data on which to found an exact 
investigation, and, having no hypothesis to support, shall 
decline entering into the enquiry. 
JoHN BLAcKWALL. 
Crumpsall Hall, May 4. 
