4. BULLETIN 217, U. S. DEPARTMENT OF AGRICULTURE. 
Salt Lake City, who were deeply interested in the work. Valuable 
information was obtained also from V. T. Davis, in charge of the 
grounds of the Bear River Club. At the mouth of the Weber River, 
W. O. Belnap gave all possible assistance, as did other members of 
the North Shore Gun Club. At the mouth of the Jordan River work 
was done at the New State Gun Club. Permits for shooting such | | 
birds as were necessary for purposes of investigation were granted | 
by the State fish and game commissioner, Fred W. Chambers. In ~ 
California the State fish and game commission furnished an assistant, | 
Tipton Matthews, deputy warden of Kern County, whose aid ren- _ 
dered the work around Tulare Lake effective. eRe 
NATURE OF THE TROUBLE. 
During the season’s work in Utah 27 species of birds of 11 families 
were found to be affected. Among these were 9 species of ducks, 10 
of shorebirds, and 8 miscellaneous forms ranging from grebes and 
snowy herons (see Pl. II, fig. 1) to the pipit. Among ducks the pin- 
tail and green-winged teal seemed to be most susceptible, while the 
mallard, spoonbill, and cinnamon teal followed them closely. Avocets 
and stilts suffered more heavily than any other shorebirds. 
The birds affected first lose the power of flight and are unable to 
rise in the air, though in some cases they can flutter across the water, 
and in others can fly for a few rods before dropping back. The legs 
next become affected and the power of diving is lost. As the birds 
grow weaker, they crawl out on the mud bars, if able to do so, or hide 
in growths of grass or rushes. In a later stage of the affection they 
are unable to rise. Finally the neck relaxes and the head lies pros- 
trate (see Pl. II, figs. 1 and 2). If in the water, death comes by drown- 
ing, but on land, birds may live for two days or more im this condition. 
A large series of postmortem examinations revealed no patho- 
logical lesions other than that the intestme was reddened and firm 
and hard to the touch. When the gut was slit, washed, and examined 
under a low magnification, the capillaries in the intestinal villi were — | 
found to be distended, showing intense irritation. The reddening 
‘of the canal appeared sometimes in spots, most severe at the bends 
of the intestine, but at others it extended continuously from the 
duodenal loop to the ceca. Clots of extravasated blood, partially — 
digested, were found in most cases, and not uncommonly the ceca — 
were distended with this matter. A severe dysentery occasioned by ~ 
the irritation of the intestine was the obvious external symptom. 
The feces were greenish and stained the feathers about the anus and 
sometimes well up on the abdomen. Large quantities of renal matter 
were present, white and almost solid, and with an offensive odor. As — 
the food residue in the intestine worked off, this renal matter con- 
stituted an increasing proportion of the feces, frequently solidifying i 
