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 sufficiently 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 effectual 
stop 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 
