8 MAKING A FISHERY. 



as Limn&a, Bythinia, Planorbis, Valvata, &c, 

 and Bivalves, such as Spkcerium, &c. ; among 

 insects, caddis or larvae of the Trichoptera, 

 larvae of the Mayfly and smaller E ' phemeridcB \ 

 of the Alder {Stalls lutaria), and of the numerous 

 small black flies (Diptera), called, in the 

 anglers' slang, curses or smuts. If the result 

 of dredging is to show that generally there is a 

 deficiency of insect life, it may be safely pre- 

 dicted that the trout will not be free risers. If, 

 in addition, the molluscse and crustaceans are not 

 very plentiful, this particular length of streajn is 

 not likely to grow a good stock of well-con- 

 ditioned fish, and is not therefore a desirable 

 one to rent. If in the future some benefactor to 

 the community can discover an easy method of 

 introducing fresh genera and species to the 

 rivers, as well as the plants on which they 

 subsist, it may be possible to effect great im- 

 provements, and thus enhance the value of 

 waters which are at present unfit for the serious 

 attention of anyone desirous of making really 

 good fishing. 

 Examination The food supply in any river is largely 



dependent on the presence of. the various weeds 

 on which so many of the larvse, &c, live, as 

 well as of the soil in which these weeds flourish. 

 In many of the north country rivers there are 

 practically no weeds, the bed of the river con- 



