68 American Fisheries Society 



trout and in summer with bass. Trout are handled by 

 the usual method being allowed as much room as prac- 

 ticable in summer and confined in winter where they can 

 be conveniently handled for egg-taking. It will be recog- 

 nized that in summer they must be held in ponds or pools 

 near the supply tank and that a good flow must be pro- 

 vided to keep the temperature down. This can be accom- 

 plished by giving the trout the smaller upper ponds and, 

 by selecting those from which part or all of the overflow 

 can be diverted from the bass ponds below, it is practica- 

 ble to avoid sending too much water into the latter. 

 Before the station was built the spring had its outlet by 

 a small stream running diagonally across the present 

 grounds and deep enough so that all the ponds may be 

 drained into it and most of them cannot be entirely emp- 

 tied except into this stream. While this outlet must be 

 used for part or all of the overflow from the trout ponds, 

 with the other sorts it is necessary to keep it tightly 

 closed while the fish are small enough to pass the screens 

 or they will do so and be lost to the station. It may be 

 thought that the overflow from the trout ponds can 

 hardly be too great for the supply of the bass ponds, but 

 it is to be considered that for bass the supply of cold 

 water may easily be too great, not only because they 

 require a rather high temperature but because the small 

 life, on which they feed, is also greatly stimulated by 

 warmth. But besides this it has been found that the 

 young fish are much more easily held in the ponds when 

 the overflow is shut off or nearly so. It is well known 

 that the young fish move about the pond when so small 

 as to be able to pass through almost any screen that can 

 be maintained and that at this stage their tendency is to 

 go down stream. When they are larger and seek the 

 intake, a larger flow may be furnished as the weather is 

 then warmer and there is less likelihood of the water 

 being made too cool. 



It is evident, therefore, that some provision must be 

 made to turn part at least of the overflow from the trout 

 ponds away from the lower ponds of their series and for- 



