192 



THE DIPPER. 



A concluding word on the remark, that " the 

 habit of the dipper walking underneath the water, 

 is too well known and authenticated to need any ad- 

 ditional information from me" [that is, from Mr. 

 Morris] . I am not a convert to the doctrine of a 

 subaquatic promenade: first, because I know that the 

 bodies of all birds float on the surface of the water ; 

 secondly, because I am convinced that birds are 

 obliged to make great exertions with their wings and 

 feet in order to be able to reach the bottom ; thirdly, 

 because I am satisfied that, as soon as they have ar- 

 rived at the bottom of the water, the force which 

 enabled them to descend to it ceases to act. Hence 

 I infer that the body of a bird, impelled to the bot- 

 tom by the aid of the feet and wings, must rise again 

 when deprived of that aid. I can easily conceive, 

 however, that the dipper, by the use of its legs and 

 wings, may manage to keep sufliciently near the 

 bottom to be enabled to turn over the pebbles with 

 its bill in quest of food ; because, in this position, 

 the legs and wings would have power to act, and 

 they would tend to counteract the rising motion of 

 the body. I maintain positively, that a bird cannot, 

 by any chance, walk on the ground under water. The 

 moment it attempted to do so, the legs and wings, 

 by the altered position of the body, would be de- 

 prived of all depressing power ; and the body itself 

 would be raised up towards the surface of the fluid 

 in which it is immersed. This would put an eflectual 

 «top to all proposed perambulations at the bottom 

 of the stream. This is only theorj^ and theory may 

 err. I often used to watch the dipper, when in 



