Birds. 753 



quickly indeed to allow of my seeing whether matter was actually 

 rubbed on them ; considering also the comparatively small quantity 

 that w r ould be expressed at each application of the bill to the gland ; 

 all this tended to convince me the bird was really doing that which I 

 had previously believed birds did not do. The whole process was 

 exactly that which might have been expected, supposing it to be a 

 fact that birds do lubricate their feathers with matter from the oil- 

 gland. 



Mr. Waterton considers that the tuft must prove an "insurmountable 

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

 of the bill." Doctors of ornithology (I am one only by the courtesy 

 of your readers), as of other sciences, must and will differ : for I, for 

 my part, can conceive even an use for the tuft, in distributing the 

 expressed matter over the interior of the bill and the surface of the 

 tongue, in order to its more equal and readier application to the 

 feathers : and therefore, it may be, the tuft is larger in the aquatic 

 birds, because their bill is broader. 



I could wish Mr. Waterton would tell us what he thinks is the use 

 of the oil-gland ; and what was the intention of the Creator in im- 

 parting it. To suppose that such an organ should have been given 

 but for a specific purpose, would, I think, be impugning the wisdom 

 of the Creator : its existence without an object would be an anomaly 

 among his works. Satisfied from analogy that where such a gland 

 existed for converting blood into a different substance, its use was 

 not less certain than its existence ; I once thought it might possibly 

 be in some way connected with the growth of the plumage : and that 

 the fluid might be conveyed to the roots of the feathers by means of 

 minute vessels traversing the skin : in short, that it might be the mat- 

 ter of which the feather is composed. The size of the gland would 

 lead us to suppose that considerable quantities of the matter were 

 formed ; and so would seem to favour this notion : but the difficulty 

 met me, what then is the use of the nipple ; and of an orifice on the 

 extremity of that nipple ? 



But this is not a subject to be decided by theoretic argument. If 

 settled at all, it must be settled by observation of facts. The liability 

 of the most plausible arguments to be overthrown by plain facts, 

 nobody has better shown than Mr. Waterton himself. Reasoning, 

 unless founded on facts, will not decide this, or any other disputed 

 point in natural history : further observation is therefore necessary. 



I have not yet succeeded, as has Mr. Hussey ( Zool. 648 ), in 

 observing this lubricating process gone through by many birds; 



