6 BULLETIN 862, U. S. DEPARTMENT OF AGRICULTURE, 
little barley (Hordeum pusillum), crab grass (Syntherisma sanguinalis), 
wild millet (Echinochloa crus-galli), foxtail (Chaetochloa glauca), cut- 
grass (Zizaniopsis miliacea), rice cut-grass (Homalocenchrus oryzoides), 
salt-marsh grass (Spartina sp.), manna grass (Panicularia sp.), Mon- 
anthochloé littoralis, and a few others, unidentified. Several of these 
were represented only by the seeds, and then they usually consti-. 
tuted a comparatively small part of the stomach contents. 
The cultivated grain was tabulated separately from the remainder of 
the grasses because of the economic interest attached to it. It con- 
sisted, however, almost entirely of rice found in the gizzards of several 
Louisiana birds taken in February, and was undoubtedly waste 
grain. Onestomach taken in Oregon in January was crammed with 
grains of barley; and another, from North Carolina in February, con- 
tained several kernels of corn. Obviously these also were of no eco- 
nomic importance. The rice, barley, and corn together amounted 
to 1.31 per cent of the contents of the whole nunvber of stomachs. 
WATER PLANTAIN FAMILY (ALISMACEAE), 3.25 PER CENT. 
One of the favorite items of food among many species of ducks in 
the lower Mississippi Valley during the fall and winter months is the 
delta potato, as the starchy tubers of a species of arrowhead (Sagit- 
taria platyphylla) are called. These constitute an especially impor- 
tant food item among ducks wintering on the Mississippi Delta, Loui- 
siana, Where the tubers grow in great abundance and-the variety of 
duck food is not great. Many gadwall stomachs from this region 
contained only oe items of food, which also have been found to be 
the typical diet of several other species when wintering on the Delta: 
these were the seeds of three-square (Scirpus americanus), the 
delta potato, and a species of snail (Neritina virginea), very abun- 
dant there: The stomach contents of a series of 27 gadwalls taken 
near the end of the Delta in November averaged as follows: Seeds of 
three-square (with a few of salt-marsh bulrush), 44.55 per cent; 
delta potato, 20.89; pondweeds, 13.78; and snails, 7.11 per cent: sev- 
eral minor items, as algae, coontail, duckweeds, and a few insects 
made up the remainder. 
DUCKWEEDS (LEMNACEAE), 0.61 PER CENT. 
It is rather surprising that a duck which shows such a marked 
preference for the foliage of aquatic vegetation as the gadwall should 
not have eaten duckweeds to a greater extent. These are small 
floating plants, often present in such abundance in ponds, lakes, and 
Soest streams as completely to cover large areas of their surfaces. 
The little plants are luscious and tender, and afford a favorite article 
of food for many species of duck. Large numbers of the gadwall 
4 Bull. 465, U. S: Dept. Agr., pp. 21-24, 1917. 
Penta My 
