THE FISHING EAGLE. 145 



scarce in the north), and finding its food by sudden plunges 

 into the water, at all natural temperatures above that of 

 freezing, the under part of the osprey is exposed to more 

 sudden changes of temperature, and also of element, than that 

 of most other birds, whether of the water or the land. The 

 sea-birds that plunge from the air into the water, generally 

 plunge head-foremost, and seize their prey with their bill, so 

 that they meet the cold, and also the resistance of the water, 

 on both sides equally : but the osprey plunges down on the 

 under part only, and seizes with the talons, the head being 

 generally above water all the time. No doubt the wings, 

 and also the tail, in part soften the dash, and the under sides 

 of them are well formed for resisting the water, but still 

 both the resistance and the change of temperature come upon 

 the under side of the body, the shape and the texture of the 

 feathers defending it against the shock ; and the downy com- 

 pactness and white colour resisting the cold, as the bird is 

 again in the air before the effect of the water can be trans- 

 mitted through so close a covering of a substance which is so 

 slow a conductor. 



That texture and colour of the feathers are more neces- 

 sary in the osprey than they are in a sea-bird, even if were to 

 suppose their habits the same ; for the fresh water of the 

 lakes and rivers, in which chiefly the bird fishes, is subject to 

 much more seasonable variation than the salt water of the 

 ocean. The scales upon the tarsi are reticulated, like those 

 on birds which actually wade into the water in search of their 

 food. 



Nor is the arming and general structure of the bird less 

 admirably adapted to its modes of life. Fishes are less sen- 

 sible of pain in any part, save the head, than land animals ; 

 and from the transverse separations of the flakes or fasciculi 

 of their muscles, they can exert their powers of swimming, 

 even though a considerable part of the flesh is cut through, if 



VOL. I. L 



