160 Question of Birds' oiling their Plumage. 



maintains the doctrine subversive of the generally received 

 one on the above head. In answering his arguments, I shall, 

 therefore, I presume, encounter all, or nearly all, that is to be 

 urged in opposition to the belief that birds do use an oil, sup- 

 plied by a gland which they possess, to render their feathers 

 impervious to water. 



In a note [VIII. 375. note # ] to a short paper of mine (on 

 the habits of the dipper), which appeared in VIII. 374 — 376., 

 I expressed a doubt as to the correctness of Mr. Waterton's 

 opinion as regarded the above question ; and I have been led 

 to the remarks I am about to make by having observed, in 

 V. 412 — 415., a paper by Mr. Waterton "on birds using oil 

 from glands; " and, to avoid any confusion, I will take his ar- 

 guments against the heretofore generally, if not universally, re- 

 ceived opinion in the order in which they present themselves. 



First, then, from the circumstance of birds being annoyed 

 by small insects or vermin, Mr. Waterton takes it for granted 

 that, when birds are seen applying their bills to their feathers, 

 &c, they are endeavouring to dislodge these insects. That 

 birds are annoyed by insects " is most true ; " but, were his 

 hypothesis correct, it seems likely that the poor birds would, 

 in time at least, eradicate the nuisance, which, in Mr. Water- 

 ton's words, " no part of their bodies are ever exempt from," 

 " and which," he says, " they so much suffer from." But, 

 after all their supposed endeavours, he himself allows that 

 " no part of their bodies " has, as yet, been freed from the 

 pest ; and, this being the case, it does not appear to me that 

 instinct would suggest to the birds a useless endeavour, or that 

 they would waste their time, accordingly, which might be so 

 much better employed. When, then, in this useless, fruitless, 

 and ineffectual supposed course, the bird has chased the para- 

 sites down to the oil gland at the root of the tail, " some 

 people," so says Mr. Waterton, " imagine that the bird is 

 procuring an oil from the gland by means of its bill, in order 

 to apply it to the feathers ; " instead of, as his theory goes, 

 being engaged in the pursuit of the insects. This, he argues, 

 can, at the best, " be but conjecture, because the feathers 

 hide from our view the operation that is going on." Now, I 

 am very willing to admit that no one has ever so far ingra- 

 tiated himself into the good graces of a bird as to get it to 

 voluntarily turn back its feathers from the gland, that we may 

 see it voluntarily engaged in carrying on the operation which 

 / suppose it to carry on (in common, I believe, with most, if not 

 all, naturalists except Mr. Waterton). But, with all due deference, 

 I beg leave to differ on this subject " toto ccelo " from the author 

 of the Wanderings ; for how stands the case ? The d priori 



