712 BULLETIN OF THE BUREAU OF FISHERIES. 



above the water on four short legs, are wire baskets, one for each egg picker, 

 into which to throw the dead eggs. The farther side of each basket, to the 

 picker's right, has a high back to stop the eggs as thrown from the tweezers, 

 thus making it unnecessary for the eyes of the picker to follow each egg, and 

 thereby facilitating the entire operation. 



THE BROOK TROUTS. CHARS. AND EASTERN SALMONS. 



For brook trout eggs {Salvelinus fontinalis) the Bureau depends largely 

 upon commercial trout raisers, eyed eggs being obtained from them at lower 

 cost than it is possible to collect from wild fish at most places or from brood 

 fish maintained only for their eggs. About 8,000,000 eggs are annually pur- 

 chased from ten to eleven dealers. For the purpose of making a just com- 

 parison as to quality and final cost of fish produced from each purchased lot 

 the eggs received from each dealer are distributed to several hatcheries, that all 

 may be alike subject to different conditions of quality and temperature of the 

 water supply- 



At some stations, however, eggs from wild trout are more satisfactory. It 

 has been found that eggs from the domesticated fish hatched and reared in 

 spring water which is not subject to seasonal variations do not produce good 

 results where the temperature of the water supplying the hatchery is below 35° 

 or is subject to variations of several degrees. Vermont and Colorado are the 

 only states in which eggs of the wild brook trout are collected in sufficient 

 numbers to stock the Bureau's hatcheries in those states as well as to have a 

 surplus for distribution to other hatcheries. It is interesting to note, further, 

 that in Colorado, where the eastern brook trout is an introduced species, the 

 eggs can be collected in greater numbers and at less cost than in any other state. 



In Vermont" eggs are obtained from trout inhabiting artificial lakes on 

 private preserves. During September and October principally, but in some 

 localities beginning sometimes as early as July and continuing into Novem- 

 ber, the fish ascend the streams in large schools on each rise of water. The 

 fish culturist has only to provide suitable racks and traps in anticipation of the 

 period of migration, constructing them in the streams that have been dammed 

 to make the lakes. The fish are dipped from the trap into adjacent pens above 

 the rack, the pens being kept covered to guard against the escape of the fish in 

 case of a possible flood. 



A field station of this character is sometimes managed by one man, who 

 constructs the trap, rack, and pens, cares for and strips the fish, and then cares 

 for the eggs, which are incubated until eyed in stacks of trays in the William- 

 son type of troughs, then are packed and shipped to the central station at St. 

 Johnsbury. 



oTitcomb, J. W.: Wild trout spawn; methods of collection and utility. Proceedings of the 

 American Fisheries Society for 1897, p. 73-86. 



