PROGRESS IN BIOLOGICAL INQUIRIES, 1938 3 
fective. Important consulting services on screens and ladders were 
also afforded to other agencies. 
This illustrates a recent trend toward the development of service 
activities as a part of the regular work of this Division. In recent 
years there has been a rapidly growing number of requests from the 
State fish and game commissions, fish and game clubs, and other 
organizations for technical services and advice in connection with 
stream surveys, stream improvement, pollution surveys, examination 
of the quality of water in hatcheries or rearing ponds, development of 
fishing lakes and reservoirs and the screening of their outlets, discov- 
ery of the causes of mortality of fish in lakes, ponds, and streams, the 
treatment of fish diseases in hatcheries, and the like in amazing 
variety. 
It is clearly recognized that satisfying these demands is a valuable 
function which the Bureau of Fisheries should render to the tax- 
payers—services that, because of their technical character, can only 
be furnished by scientifically trained personnel. There is a serious 
question, however, to what extent the funds appropriated for investi- 
gation in a field which so urgently needs the development of funda- 
mental scientific principles should be applied to routine activities 
which, while locally useful, contribute little to fishery science. Obvi- 
ously a balance between original research and these practical services 
should be maintained, for the requests for service are so numerous 
that if an attempt is made to satisfy them all the major program 
of scientific investigatiton would be handicapped. 
It is not suggested that the Hydraulics Section will not make 
important contributions to the conservation of the fish supply, par- 
ticularly in the Northwest where extensive irrigation projects consti- 
tute a major hazard to migrating salmon and trout, nor that the 
studies in connection with the design of fishways or screens will not 
contribute also to an understanding of the habits and requirements of 
these fish. The Hydraulics Section, however, is primarily a service 
agency and hence is properly financed by a separate appropriation. 
Normal development and improvements, including minor modifica- 
tions or extensions of activities, have occurred in all of the other 
major research projects of the Division, the details of which will 
appear in the following reports of progress. 
COOPERATION 
In previous reports the Bureau has been pleased to acknowledge a 
growing spirit of cooperation in fishery research among the various 
governmental departments, the States, and private organizations. 
This trend has been continued during the past year without abate- 
ment. Outstanding examples of cooperation in fishery conservation 
are afforded by the United States Forest Service, United States 
Bureau of Reclamation, the Coast Guard, and the Tennessee Valley 
Authority. Many States have likewise contributed either by actually 
furnishing funds, personnel, or other facilities, or through a less 
tangible but an equally real spirit of sympathy and support. | | 
The most ambitious cooperative project undertaken by the Division 
of Scientific Inquiry during the year was a survey of the marine 
