114 FISH CULTUEE. 



fed witli a mixture of all three species of food, 

 the fish in it would have far exceeded any of the 

 others in weight and condition. 



Some rivers notoriously produce larger trout than 

 others, although the character of the soil they flow 

 through may to all appearance be very similar. I 

 will instance two, both of which are tributaries of 

 the Thames — the Chess, a branch of the Bucking- 

 hamshire Colne ; and the Wick, a little stream run- 

 ning through High "Wycombe. I select these two 

 streams because they are only some ten or twelve 

 miles from each other, and because they are as 

 nearly as possible of a size. Now, it is generally 

 supposed that the very best and most fattening food 

 provided by ^Nature for the trout is the may-fly, or 

 green-drake. This fly abounds in profusion on the 

 Chess ; it is rarely if ever seen on the Wick — in fact, 

 it may be said not to exist there. The minnow, like- 

 wise supposed to be most excellent and nourishing 

 food for the trout, is also a stranger to the Wick ; or if 

 it exists there, is not found in any considerable number. 

 Sticklebacks and miUer's thumbs are found in places, 

 though they do not abound in all parts of the stream. 

 The caddis, or case grub of the smaller flies, however, 

 is very ^.bundant ; and in some of the hatch holes 

 J;here are a considerable quantity of leeches. 



