2 90 . ELEMENTARY ZOOLOGY 



many food-fishes which cannot be handled in this way. 

 In some the eggs are small or soft, or viscid and adhering 

 in bunches. In others the life-habits make artificial fer- 

 tilization impossible. Such species are artificially reared 

 only by catching the young and taking them from one 

 stream to another. To this type belong the black bass, 

 the sunfish, the catfish and other familiar forms. 



