The Seal Tribe. 125 



being used as an aid to progression more upon dry 

 land than in the water. Indeed, when the seal swims, 

 it presses the fore-feet, or flippers, as they are called, 

 against the body. The hinder feet, however, which 

 are not rudimentary as in the whales, but are flat and 

 broad, serve both to propel the body through the 

 water, and also as a rudder to direct its course. And 

 this is managed in a manner very different to what we 

 might expect. The feet do not beat the water, 

 like those of the duck or frog, and thus answer 

 the purpose of oars, but are placed side by side, thus 

 forming a single paddle, set edgewise, like the tail of 

 a fish. These united feet being then swept from side 

 to side, the animal is driven along by the action against 

 the water, a slight alteration only of their position 

 being required in order to direct the course. 



By the aid of this simple means of progression, the 

 seal is enabled to traverse the water with wonderful 

 speed, and at the same time with an easy and undu- 

 lating grace which is equalled by no other creature. 

 This peculiar motion is owing in a great measure to 

 the flexibility of the spine, which allows the body to 

 be bent with facility in almost any direction. 



Once upon dry land, however, the graceful move- 

 ments degenerate into an ungainly shuffle, and the 

 animal reminds the observer of some huge and over- 

 grown caterpillar crawling awkwardly along. The 

 fore-limbs now come into play, and the animal scuttles 

 along, clumsily enough, it is true, but yet with con- 

 siderable speed. 



The nostrils and ears are provided with the means 

 of preventing the ingress of water when the animal 

 dives below the surface, the former closing by their own 

 elasticity, while the latter are furnished with a structure 

 analogous to that found in the whales. There is 

 a curious point concerning the locality of the external 



