272 NATATORES. 



and rounded. The foot, of which the following is a sketch, 



is a very singular instrument, and perhaps the best formed of 

 any of the feet even of swimming birds for getting through 

 the water, and for acting both as oar and rudder, when the 

 bird is under the surface. The bird does not paddle, but 

 row, striking out both feet at once, and turning them so that 

 the flat side of the tarsus and the webs of all the toes strike 

 the water at the same instant ; and, by means of the rolling 

 motion, the stroke can be given obliquely in any direction. 

 To construct a paddle that could act wholly in the water, 

 upon the model of the grebe's foot, would be a vast acqui- 

 sition in the art of propelling vessels. 



When on the surface, the grebes swim swiftly and beauti- 

 fully, and under water they use their wings in swimming ; 

 and their motions resemble those of frogs. The feet are 

 placed wide, and they are recovered with the edge turned, 

 as rowers " feather " their oars. The birds have the most 

 perfect command of the water. They can take wing from it, 

 alight in it, dash along the surface heedless of wave or foam, 

 dive, shoot along below, come up again, and play about just 

 as they list. They are, perhaps, also, the most completely 

 waterproof of all the feathered tribes. There is never a 

 humid feather or the least trace of wet upon a grebe, unless 

 there be a dead feather or a wounded place, even though it 

 has been driving about for an hour under water. In the 

 course of its under- water excursions it comes up to breathe, 



