206 MR. A. H. REID 



enables those interested to examine and repair the 

 gravel beds in the off season, and to personally snpervise 

 and protect the alevins from their land and air enemies 

 by covering the channels with wire netting. In due 

 course the sluices can be opened and the fry will scatter 

 in search of food and shelter. As a rule they seem to 

 prefer rather rapid and shallow water to that which is 

 sluggish. Their food by selection is molluscs and fly 

 larvae from under stones, water fleas, and other crus- 

 taceans. But their struggle for existence is a hard one 

 in view of the many enemies that await them and of the 

 fact that our streams, unless they are open to back 

 waters, or swamps, do not provide sufficient aquatic life, 

 for winter floods devastate their banks and remove the 

 vegetation upon which the fly larvae exist. It is very 

 interesting to watch the fry working their way down- 

 stream on their first journey. They seem to be all on the 

 '' qui vive '' and continually plucking or eating some- 

 thing when they stop to have a rest. They travel in 

 short stages with their tails first and heads upstream 

 so that the flow of water carries them down, but directly 

 they strike slow or stagnant water they bolt off with 

 their heads downstream until they pull up behind a stone 

 or some other shelter and have a rest. In some waters 

 however the passage is a perilous one, as the big fish 

 wait for them in the main river. 



Food Supply. 



Backwaters and swamps are the breeding grounds of 

 just those forms of aquatic life that provide the most 

 desirable food for trout, and there are many such quite 

 close to our rivers that could be easily connected thereto 

 by simple channels. Then again many irrigation fur- 

 rows could be converted into excellent food waters for 

 ^^'J by judicious widening and weed planting: wire 

 screening could be arranged to prevent bigger fish from 



