6 BULLETIN 672, U. S. DEPAETMEKT OF AGMCTJLTUKE. 
and many ducks. A few birds were still affected after the 1st of 
October. Individuals examined at this time had the same malady 
as the ducks in Utah, but it can not be stated definitely that all had 
died from this trouble. 
Sick birds in large numbers were reported in the Cheyenne Bottom^, 
near Great Bend, Kans., in 1914 and 1915. From information fur- 
nished by Dr. X. P. Sherwood and Dr. B. T. Clawson, of the University 
of Kansas, it would seem that these may have been suffering from 
some bacterial affection. 
Other reports more or less indefinite have come from other regions 
in the West. 
OUTLINE OF FIELD WORK. 
A preliminary examination and study of conditions was begun by 
the writer in the Salt Lake Valley on July 12, 1914, and continued 
without interruption until October 30. Conditions on the Bear, 
Weber, and Jordan Rivers were studied thoroughly, and visits were 
made to the Willard Spur, Promontory Point at the southern end of 
the Promontory Range, and Locomotive Springs, a large isolated 
marsh area on the northern shore line of Great Salt Lake near Kelton. 
In connection with this work the writer visited the Tulare Lake basin, 
in California, from November 3 to 11, where he was assisted i 'aterially 
by Tipton Matthews, deputy warden of Kern County, whc h services 
were made available through cooperation of the California Fish and 
Game Commission. Following this, conditions were studied at 
Owens Lake, Cal., from November 12 to 14. 
In 1915 work was begun in Utah on May 15 and continued until 
October 25. As the investigations of the previous year had estab- 
lished that the affection was apparently identical in the three large 
areas involved, it was decided to carry on intensive work in one area 
and to visit the other regions when necessary. The marshes and 
shallow bays in the delta of Bear River at the northern end of Great 
Salt Lake, offered a great expanse in which conditions were varied 
and in which waterfowl were enormously abundant. A small tem- 
porary field laboratory was erected here, and pens and cages for use 
in experimental work were built as needed (PI. IV, fig. 2). This year 
was unusually dry, and large areas were bare which were covered 
with water under normal conditions. The New State Gun Club 
marshes were drained by order of the club authorities early in the 
year and remained dry during the whole summer season. The entire 
volume of water in the lower part of the Weber River was taken out 
for irrigation, and the flats at its mouth were dry until fall. On Bear 
River the amount of water in the stream was greatly reduced, and 
large marsh areas, normally covered with from 1 to 10 inches of water, 
dried and baked in the sun. North Bay was dry, but a part of South 
Bay remained, and here many ducks congregated. Work was carried 
