in several Species of Birds, 403 



denuded state of the nostrils and the anterior part of the head, 

 both of which are entirely destitute of feathers. Another 

 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 evident that 

 the bird, possessing a bill thus formed, could not thrust it into 

 the ground in search of worms and the larvae of insects, as 

 the rook is known to do habitually; and, accordingly, the 

 plumage at the base of the biU 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 erythrocephalus), 

 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 alone excepted, in which the direction is reversed), cross- 

 ing the lower one on the right side. A bill so constructed 

 must have 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. 



