212 FIRST LESSONS IN ZOOLOGY 



haps, because they hve in the swiftest and clearest 

 waters in the most cliarming" forests. The sahnon hve 

 in the ocean most of their lives, but ascend the rivers 

 from the sea to deposit their eggs. The king salmon of 

 the Columbia goes up the great river more than a thou- 

 sand miles, taking the whole summer for it, and never 

 feeding while in fresh water. Besides the different kinds 

 of salmon the black-spotted or true trout, the charr or 

 red-spotted trout of various species, the whitefish, the 



Fig. 171. — The r;iinbi)W-trout. Sabno iridcus. (From specimen.) 



grayling, and the famous ayu of Japan belong to this 

 family. 



In the sea are multitudes of fish forms. The myriad 

 species of eels agree in having a long, flexible, snake- 

 like body, without ventral fins. Most of them live in the 

 sea, but the single genus of true eels which ascends the 

 rivers is exceedingly abundant and widely distributed. 

 Most eels are extremely voracious, but some of them 

 have mouths that would barely admit a pin-head. Cod- 

 fishes are creatures of little beauty but of great useful- 

 ness, swarming in arctic and subarctic seas. The her- 

 ring, soft and weak in body, are more numerous in indi- 

 viduals than any other fishes. The flounders, of many 

 kinds, lie flat on the sea bottom. They have the head so 

 twisted that the two eyes occur both together on the 



