THE SUN-PERCH AND THE CATFISH 



scales combine the most gorgeous sparkle with an 

 astoundingly varied wealth of colour. It is indeed a 

 moving jewel. 



" With these two species we made a definite advance. 

 They are really useful. They are not so difficult to 

 raise as our native trout; they grow more quickly, and 

 are easily collected and fed in the tanks where they are 

 raised for the market. But this is as far as we can go. 

 If any attempt is made to restock free-flowing waters 

 with them, it almost always fails. The fisherman 

 waits for results, but he is invariably disappointed." 



Fig. 41. — Rainbow Trout. Its length may be as much as 2 feet. 



The young man interrupted him. " But why? If 

 these fishes accommodate themselves so well to a con- 

 fined existence, where one would expect them to perish 

 just because they are confined, why don't they get on as 

 well, or better, when they are in free water, with un- 

 limited room to move about? " 



" I'll tell you why in due course," the father replied, 

 " but I must first complete my account of our attempts 

 at acclimatization. Meanwhile, I can throw some light 

 on the matter by making a comparison. Think of the 

 other animals we breed for our own purposes, animals 

 which can only exist so long as we look after them, and 

 would inevitably perish if we set them free. The 

 slavery of domestication is absolutely essential to them. 

 Look across the river at the turkeys and guinea-fowl 

 pecking about in the meadow on the other side, looking 

 199 



