Birds, 675 



" He has quite satisfied me that the windhover will now and then make a meal on 

 the smaller birds ; and this information on his part is very acceptable to me, as I have 

 no opportunity of observing the windhover during the winter months, for it leaves this 

 immediate neighbourhood in October, and seldom returns before the first week in 

 February. 



" The conclusion of Mr. Bury, as to the use of the oil-gland, is not quite so satis- 

 factory. He says, " And I plainly saw the bird press the nipple with its beak, and rub 

 the matter so expressed on its feathers." This assertion would have put the question 

 at rest for ever in my own mind, and I should willingly have yielded the disputed palm 

 to this intelligent gentleman, had he not subsequently remarked, " I do not mean to 

 say I ever saw the matter expressed." 



" Now he ought to have seen the matter expressed. The bird was on his finger, 

 " under a strong light," and this position afforded him the very best opportunity of 

 seeing the matter, which is an opaque and palpable substance, and could not possibly 

 have escaped the notice of so keen an observer as Mr. Bury, had it really been rubbed 

 on the feathers, and even transferred, as he says, from the feathers of the body to those 

 of the head. I can assure him that I have witnessed a favourite parrot press its nip- 

 ple scores of times, but I could never detect the least moisture on the sides of its bill, 

 nor observe the smallest portion of matter on the feathers which the bird was preen- 

 ing ; hence I came to the conclusion that the parrot had pressed the nipple, not to 

 procure the substance which it contained, but merely to gratify itself by producing 

 that pleasing sensation which we ourselves experience when we rub our dry hand 

 over our face. 



" Again ; in most waterfowl, the oil-gland is completely covered with a thick tuft 

 of down, not moveable at pleasure, like the true feathers. This tuft would prove an 

 insurmountable obstacle to the transfer of matter from the gland through the medium 

 of the bill. In fine, there are some birds without any gland at all, as I have remarked 

 elsewhere. Providence never does anything by halves. If the matter from the oil- 

 gland were for the purpose of lubricating the feathers, it would not have been granted 

 by the Creator to one bird, and denied to another. Had such an act of partiality ta- 

 ken place, " it would have been putting one sadly over the head of another." 



" Some years ago, when I was in hot dispute on this subject with writers in Mr. 

 Loudon's * Magazine of Natural History,' a thunderstorm provided me with the means 

 of having a very satisfactory view of the oil-gland on the rump of a kestril or wind- 

 hover. The poor hawk was sitting upon the branch of a sycamore tree, when the 

 lightning struck it dead to the ground. It was a fine old male bird, and had no out- 

 ward marks of damage on it. I carefully dissected the oil-gland. Around the base of 

 it there was a circle of down. The shaft of the nipple was quite bare of down or fea- 

 thers ; but the orifice of the nipple was totally concealed by a very dense tuft of down, 

 which had the exact appearance of a camel-hair brush. 



" Had this kestriPs intention been ever so ardent to lubricate its feathers with the 

 contents of its own oil-gland, the thing would have been impossible, because the thick 

 bunch of down, on the very extremity of the nipple, would have effectually impeded 

 the transfer of the oil from the gland to the bill. Moreover, the oil would have disfi- 

 gured the down, had it been expressed through the nipple ; and Mr. Bury could not 

 have failed to observe the change which the oil would have made in the aj pearance of 

 the down itself. The tail and oil-gland of this kestril are now on the table before 

 me."— p. 130. 



