THE CONQUEST OF THE DRY LAND 205 



cise ; fumbling and stumbling are fatal. But im- 

 provement of movements means a more com- 

 plicated muscular equipment and a more effec- 

 tive controlling (or nervous) system. It is fair to 

 say that the brain was the controller of move- 

 ments long before it was a thinking organ. 



We do not mean that the movements of. 

 aquatic animals are not admirable. The swim- 

 ming fish or squid cannot be surpassed. We 

 mean that the freedom of movement in the 

 water allows a certain leisureliness (in jelly- 

 fishes, for instance) which is impossible on 

 land, unless there is some compensating pe- 

 culiarity, such as coming out at night. No ani- 

 mal moves at random, but the water animal 

 has a wider range of alternatives than a land 

 animal. And it is not only that land animals 

 are confined to one plane ; unless they learn to 

 burrow, or climb, or fly, they have to follow 

 their food with a new strenuousness. In the 

 open sea, the deep sea, and the fresh waters, and, 

 to some extent, on the shore, food is sometimes 

 brought to the hungry animal, but it is very 

 seldom that this can be said to occur on land. 



It must be noted, however, that an appren- 

 ticeship to quick, precise movements, such as 

 land animals require, was probably served on 



