PROGRESS IN BIOLOGICAL INQUIRIES, 1938 69 
construction of three dams on the American and Yuba Rivers in Cali- 
fornia. Data were gathered during the summer by standard stream 
survey methods and, in addition, two men were employed to count 
salmon ascending the rivers. The counts were incomplete and do not 
include a reputedly sizeable steelhead trout run. They do, however, 
indicate that it will be mainly sport fishing and not the commercial 
salmon fishery that will be affected by the dams and mining debris. 
Survey of Pyramid Lake, Nevada—A survey of Pyramid Lake 
and its fisheries problems was made between March 7 and June 8 at 
the request of the Indian Service. Francis H. Sumner was stationed 
at the lake to gather biological, physical, chemical, and historical data 
on the lake and on Truckee River, which formerly was the spawning 
ground of great runs of cutthroat trout. With the aid of Indian 
wardens a record was kept of the commercial catch made by the 
Indians, which has declined greatly in recent years. Length-fre- 
quency and age studies show that the run is at present made up 
almost entirely of old fish, averaging 34 to 35 inches long, and that 
the younger age groups are not represented. This age and frequency 
is the reverse of that usually found in an over-exploited fishery. It 
appears that the run was but a remnant of a race that has practically 
ceased to reproduce, from lack of spawning facilities. Overfishing by 
the Indians has probably been a factor in depleting the run, but it is 
evident that the diversion of the Truckee River water has been the 
major cause. It is considered doubtful that rehabilitation could be 
effected by any means. 
BASS 
Studies on streams in Virginia and West Virginia—Field work on 
bass streams, begun in 1936, was continued at the Leetown (W. Va.) 
station by E. W. Surber and George E. Klak. 
These studies are designed primarily to determine the extent and 
efficiency of natural propagation of bass and the effect of intensive 
fishing on the bass population. They show that, even in heavily 
fished waters, there is little danger of the bass population being 
seriously depleted if adequate spawning facilities are available. In- 
tensive fishing frequently results in excessive numbers of small bass, 
with consequent reduction in the abundance of forage fishes. It is 
apparent that the remedy is to build up the food supply and that 
stocking with young will only tend to intensify the unbalanced 
condition. 
Monthly series of bottom samples were collected from the experi- 
mental sections of four streams, namely, the Cacapon River, South 
Branch of the Potomac River, North Fork of the Shenandoah River, 
and the Shenandoah River. This series of samples duplicates those 
taken in previous years. Special attention was given to measure- 
ments of current velocities at all sampling stations. Laboratory work 
on the bottom samples has been completed, but the data have not yet 
been analyzed. : 
Studies of the extent of natural propagation were continued in 
these four rivers. In contrast with previous years, interruption of 
the spawning season by cold weather and muddy waters brought 
about a second spawning early in June. In previous seasons spawn- 
ing was completed by the 1st of June. The number of bass nests 
