UNITY OF SYSTEM. 27 



bill cannot reach, is then rubbed over the parts where this extra quantity 

 of oil is placed, so that by turning the head and neck on either side, all 

 those feathers out of reach of the bill are as regularly and effectually 

 lubricated as any other part of the body. 



Waterton also remarks, "Granting glands to supply an oily secretion, a 

 sufficient quantity could not be obtained to lubricate all the feathers." 



Why not? It is known that the bones of swimming birds are not hollow 

 like those of other classes, but are filled with oily marrow; and that the 

 glands spoken of are well supplied, is evidenced by the appearance of 

 these parts even after the death of the bird. Where then is the difficulty 

 in believing the oily liquor to be supplied in sufficient quantity? Besides, 

 it does not necessarily follow that so large a proportion is required at one 

 time. The secretion being continuous, and the operation of lubrication 

 frequent, removes that objection; and as to the extraction of the oil 

 from the soft gland by the sharp bill of the bird being a painful operation, 

 it is all nonsense, for it is evident the bill is not so used, but is merely 

 rubbed against the gland as already described. The necessary state of 

 lubrication is therefore accomplished without incurring any of the difficulties 

 enumerated by Waterton; and without the defence of such preparation, 

 how is the fact of water running off the plumage of birds like quicksilver 

 to be accounted for? 



Weston Road, Bath, October lOtk, 1856. 



ON UNITY OF SYSTEM. 



"Thro' ceaseless change to seek th' unchanging." 



There is a universal law of creation as beautifnl as it is simple, and 

 apparent throughout nature, and in all creatures, collectively and individually, 

 and rising through successively higher manifestations, till it is lost to us 

 in unrevealed mysteries. 



This is the law of degradation, or of subjection, by which the cessation 

 of one state or epoch, or at least the diminution of its most perfect con- 

 dition must precede the development of the ensuing and higher degree of 

 existence. By this law the means are continually more and more subject 

 to the end, in which they at last disappear or cease. The examples afforded 

 by Geology are very numerous, and a few are here selected, wherewith to 

 commence the illustrations of this law: — 



The earth during very many millions of ages was gradually cooled from 

 an incandescent mass to its present state, and the latter part of this period 

 was marked by numerous successive epochs, in which the great divisions 

 of the animal, such as Radiata, Mollusca, Fishes, Reptiles, Birds, and 



