298 REPORT OF THE SECRETARY OF THE INTERIOR 
is a definite sequence of runs bound for different sections, and that a 
large proportion of the sockeye which passed were not subsequently 
observed in the estimation of the spawning population. 
During the year a biometric study was made of the races within the 
Fraser and in other rivers to which sockeye caught with Fraser River 
fish are bound. A great mass of data was collected and has now been 
analyzed in part. 
The experiments at Cultus Lake with methods of estimating escape- 
ment were carried further. At the same time the experiments on the 
control of predators and the factors influencing the survival of young, 
as well as their natural history, originated by the Fisheries Research 
Board of Canada, were continued. 
The collection of statistics and materials for a general history of 
the Fraser River and its sockeye runs was continued on an extensive 
scale. 
COOPERATION WITH FEDERAL, STATE, AND OTHER AGENCIES 
The Division of Fish Culture is vitally concerned in placing its 
product—fish and eggs—in environments where the greatest dividends 
will be derived from stocking. Because the Bureau’s staff of biologists 
has been entirely inadequate to conduct surveys of all the inland 
waters of the United States, fish applications from individuals and 
clubs are submitted to more than 20 State fish and game commissions 
for approval before stocking the specified waters with the species 
requested. In some States the authorities stipulate the species, num- 
ber, and size that will give best results, while in others the stocking 
programs have been formulated and the combined output of the State 
and Federal hatcheries has been budgeted to conform to these pro- 
grams. The exchange of eggs and fish, especially trout (Salmonidae) 
and related species, has been of mutual benefit in a number of States. 
In view of the tremendous amount of angling in the waters within 
the national forests, there has been close cooperation between the For- 
est Service of the Department of Agriculture and the Bureau in 
an effort to maintain good fishing in those areas. More than 20,449,000 | 
fish were assigned to the Forest Service for the stocking of suitable 
waters during the past year. Trout-rearing units were operated in 
the Chattahoochee, Natahala, Pisgah, Allegheny, Huron, Marquette, 
Chequamegon, and Superior National Forests, and approximately 114 
million trout were reared to large fingerling, or legal size before 
liberation. 
The Bureau continued to cooperate with the National Park Service 
in the restocking of waters under its control. It appears that an all- 
time record will be established with regard to the number of black- 
