714 BULLETIN OF THE BUREAU OF FISHERIES. 



three years, and possibly more often, at some period during the spawning season 

 there is a procession of fish in twos, threes, and fours around this island. They 

 follow the indentations of the shore line closely. There is no apparent break in 

 the procession, the line being visible from any view point on the shore. It 

 usually continues, moreover, for several days. A 200-foot Baird collecting seine 

 run from the shore line of the island to form an obtuse angle intercepting the 

 run for ten minutes will he full of fish. The spawntakers, standing about the 

 bag of the seine, in two or three feet of water, proceed to strip the fish in the seine 

 while the procession closes in, the line of trout winding in and out about the 

 legs of the men and apparently in as large numbers as before. 



The spawntakers with their full pails of spawn proceed to a station near 

 their headquarters, where all eggs are spread on trays and the latter are stacked 

 closely in Williamson troughs supplied with water from an adjacent lake. Here 

 the eggs are eyed preparatory to shipping a portion of them to the Leadville 

 and other stations. Some are hatched at the field station to replenish the 

 waters from which they were collected, or other waters in the vicinity. 



REARING METHODS. 



At most stations a portion of the fry are reared to fingerlings, and at some 

 stations it has been found advisable to carry brood fish, both of brook trout 

 and rainbow {Salmo irideus). 



The latter, a native of the streams on the Pacific coast, has been domesti- 

 cated and successfully propagated at stations in Missouri, Iowa, Virginia, West 

 Virginia, and Tennessee. At stations farther north whose minimum water tem- 

 perature is usually lower and subject to extreme changes, it has been cultivated 

 with varying, but on the whole rather negative, results. It has been successfully 

 acclimatized in some of the more northerly states, notably in Michigan; but it 

 does not thrive in waters subject to extremely low temperatures during the 

 winter months, and in New York and the New England States has proved in 

 most streams a failure. 



The domesticated brood fish of either species are usually the product of 

 eggs collected from wild fish, and are reared in the usual manner. The young 

 fish may be confined for the first four or five months, or until 3 to 5 inches in 

 length, in the hatching troughs or in a battery of outdoor rearing troughs of 

 dimensions and in other respects quite similar to the indoor troughs, about 12 

 feet long by 14 inches wide. Care must be taken, however, to guard against 

 overcrowding as the alevins increase in growth. The actual number of young 

 fish of a given age which can be successfully carried is dependent upon the 

 quality of the water supply, temperature being an important factor, not only as 

 to the number for a given space, but also as to their rapidity in growth. At 

 the White Sulphur Springs (W. Va.) station, with a supply per trough of 10 



