232 BIRD WATER TRESPASSERS. 



worms, and as it is not able to pull their tough cases 

 to pieces while in the water, it takes them ashore, and 

 there extracts the fat white grub from its dwelling- 

 place. It is worthy of notice, by the way, that the 

 length and development of the feet, which do the bird 

 such service in the water, render its gait on land a 

 peculiarly awkward one. 



Objections have been raised to the peculiar move- 

 ments of the Dipper while under water, and many 

 persons have doubted whether it really does walk on 

 the bottom of the stream. Their chief argument and 

 it is certainly a strong one is, that the natural 

 buoyancy of the body would cause the bird to rise to 

 the surface, so that the action of walking must be im- 

 possible. To this argument, however, it was replied, 

 that as the bird had been repeatedly seen walking 

 under water, no amount of opposite theory could alter 

 a fact. Moreover, the action of the Dipper was not 

 that of the same bird when walking on land, for in 

 the former case the bird clings to the bed of the river, 

 and by so doing is able to force its way against the 

 stream. 



Another argument might also be used, which I 

 believe has not as yet been brought forward. In the 

 " Annals of Sporting/' there is a passage which seems 

 to me to afford a key to the problem. An observer 

 was watching the proceedings of five Dippers, probably 

 the parents and their three children. 



"They next entered the water and disappeared, 

 but they did not all do this at the same time, neither 

 did they do it in the same manner. Three of them 

 plunged overhead instantaneously, but the remaining 



