212 LETTERS TO MARCO xxxn 



The rumbling rivers now do warm, 

 For little boys to paddle ; 

 The sturdy steed now goes to grass, 

 And up they hang his saddle. 



BEAUMONT AND FLETCHER. 



I now enjoy much sitting on the steps of 

 our landing-stage, in the warm sun, watching 

 the small bleak, chub, roach, etc. The little 

 bleak are rotund with spawn ; at least they 

 were so last Sunday, the 8th ; but some fish 

 must have spawned much earlier, as I noticed 

 shoals of minute fry. Fish swim by almost 

 the exactly opposite method to that by which 

 a bird flies. Birds propel themselves with 

 their wings and steer with their tails, whereas 

 fish propel themselves with their tails and 

 steer with their fins or wings. 



The dart forward is accomplished entirely 

 by the action of the fish's tail, the pectoral 

 fins being tightly closed to the sides. These 

 pectoral fins are principally used for backing 

 or stopping. The bird's tail, as I formerly 

 mentioned, serves as a very powerful brake 



