162 Retrospective Criticism. 



in Orkney). Mr. Drosier found the nest of this species, Pro- 

 cellaria pelagica L. (as well as that of the Manks puffin, Pro- 

 cellaria Piiffinus, L.) in the fissures, high up, of " one of the 

 most magnificent and stupendous cliffs, or faces of rock, — 

 estimated to be about 1500 feet above the level of the sea" 

 — he had ever beheld: this was on the southern side of the 

 Island of Foula. For Mr. Drosier's clear contradistihctive 

 description of the eggs and nests of these two species (which he 

 found in the same situation), see Vol. III. p. 325, 326. After 

 all, the remarks in Vol. V. p. 589. naturally suggest the ques- 

 tion, is it not possible that Mr. Scarth's and Mr. Drosier's 

 " stormy petrels * may have been of distinct species ? — 

 J. D. 



On Birds lubricating their Plumage from an Oil Gland. 

 (p. 588.) — Sir, Mr. H. Henslow doubts the truth of Mr. 

 Waterton's assertions with regard to birds lubricating their 

 plumage from an oil gland. In support of his doubts, he 

 brings forward a tame turtle dove, of whose actions he gives 

 a short description, but by no means a satisfactory one. I do 

 not think that there is any sufficient authority for saying that, 

 when the bird moved its head and neck about in the manner 

 he describes, it did so in order to allow the substance pro- 

 cured to spread into all parts of the bill. He confesses, 

 however, that he was not able to tell what that substance 

 was; and it is very evident that his " remarks" on Columba 

 Turtur prove nothing at all. Perhaps Mr. Henslow will 

 allow that the kestrel (Fa*lco Tinnunculus L.) approximates 

 much nearer to the bird of Washington eagle than a turtle 

 dove does. If it be so, I possess two. One of these is about 

 a year and a half old, the other a young bird of the present 

 season. The oldest is a male ; and, though both frequently 

 dress and arrange their plumage with their powerful bill, I 

 never could observe them apply it to their rump at all, much 

 less exhibit those extraordinary gestures which he describes. 

 I may add, that the jackdaw (Corvus Monedula L.), whose 

 habits resemble those of the whole order to which it belongs, 

 is another bird which uses no oil. I am, Sir, yours, &c. — 

 William G. Barker. East Witton, July 23. 1832. 



The Means by 'which the Turkey Buzzard (Vtdtur Aura L.) 

 traces its Food. (p. 83.) — Sir, I feel that Mr. P. Hunter 

 (p. 83.) is much too complimentary. In answer to this 

 gentleman's remark, that my account of the habits of the 

 Fultur Aura is at variance with the observations of Wilson, 

 Humboldt, and Azara, I beg to inform him, that I pronounced 

 the Fultur Aura of Guiana to be not gregarious, after the 

 closest attention to its habits, for a long series of years ; and 



