800 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [8] 



The change in our methods of handling the trout, namely, rearing 

 them at the station and distributing after they have attained a length 

 of 5 inches to 6 inches has, on the other baud, met with most encourag- 

 ing success. The irideus has been established in several of the streams 

 of southwest and Piedmont Virginia, and in Maryland and in a num- 

 ber of ponds in Virginia and Tennessee. 



A remarkable comparison of the different results of the two methods 

 is given by the experiments conducted under my own observation and 

 direction with a view of stocking the natural trout stream flowing 

 through the grounds of the station. For several years in succession 

 this stream was stocked with the fry of both the California and Eastern 

 brook trout. The aggregate number planted was not much short of 

 100,000. No appreciable results followed from this work. In August, 

 1886, about 400 fingerling trout from 4 to 5 inches in length were re- 

 leased into the stream. During the ensuing fall and winter about 100 

 of these were captured at the head of a little fishway fed by the waste 

 water discharged from the ponds. They had attained a length of 7 to 

 8 inches, and the brightness and clearness of their color were in 

 marked contrast to the duller hues of the fish of same age intheponds. 

 An examination of the stream subsequently showed that the trout were 

 still quite numerous in the stream in the vicinity of the hatchery. 



The important lesson to be drawn from these experiments is that in 

 stockiug streams infested by small predaceous fish we can only assure 

 success by stocking with trout of sufficient size to dominate the water. 

 Under the circumstances indicated experience, shows that several hun- 

 dred yearling trout are sufficient to stock a stream presenting suitable 

 habitat. On the other hand, we can rarely expect success in stocking- 

 such waters with any number of the fry, however great. It may be as- 

 sumed as a rule that a pair of yearling trout are fully the equivalent of 

 several thousand fry in stocking streams presenting the conditions to 

 be found in the trout region of Pennsylvania, Maryland, Virginia, and 

 States farther to the south. 



Washington, D. C, November 19, 1887. 



LIST OF PLATES. 



Plate I. — W{*cer supply and ponds for brood fish. 

 II.— General view of buildings and grounds. 

 III. — Plan of hatchery, first floor. 

 IV. — Plan of hatchery, second floor. 

 V. — View of interior, showing details of equipment. 

 VI. — General view of ponds. 



