NATURAL THEOLOGY. 73 



from the most ancient times of the world. The 

 first race, by the daily loading of the back, would 

 probably find a small grumous tumour to be form- 

 ed in the flesh of that part. The next progeny 

 would bring this tumour into the world with them. 

 The life to which they were destined would in- 

 crease it. The cause which first generated the 

 tubercle being continued, it would go on, through 

 every succession, to augment its size, till it attain- 

 ed the form and the bulk under which it now ap- 

 pears. This may serve for one instance : another, 

 and that also of the passive sort, is taken from cer- 

 tain species of birds. Birds of the crane kind, as 

 the crane itself, the heron, bittern, stork, have, in 

 general, their thighs bare of feathers. This pri- 

 vation is accounted for from the habit of wading 

 in water, and from the effiect of that element to 

 check the growth of feathers upon these parts ; in 

 consequence of which, the health and vegetation 

 of the feathers declined through each generation 

 of the animal ; the tender down, exposed to cold 

 and wetness, became weak, and thin, and rare, 

 till the deterioration ended in the result which we 

 see, of absolute nakedness. I will mention a third 

 instance, because it is drawn from an active habit, 

 as the two last were from passive habits ; and that 

 is the pouch of the pelican. The description which 

 naturalists give of this organ is as follows : "From 

 the lower edge of the under chap, hangs a bag, 

 reaching from the whole length of the bill to the 

 neck, which is said to be capable of containing 

 8 



