FOOD HABITS OF SHOAL-WATER DUCKS. 19 
often eat also the stems, leaves, buds, and tubers of some species of 
Potamogeton, leaves and rootstocks of ditchgrass, and parts of the 
foliage of bushy pondweed, eelgrass, and horned-pondweed. Pota- 
mogeton (usually seeds) was found in 250 stomachs. In a few in- - 
stances the species were identified, the most common being sago 
pondweed (Potamogeton pectinatus); but usually it was useless to 
attempt to identify species by the seeds, as they are so much alike as 
to be indistinguishable in the worn condition in which they are 
found in the stomachs. Seeds of this genus, however, even when 
present in small fragments, are easily distinguished from other seeds 
by the peculiar curved shape of the cavity which contains the em- 
bryo. The seeds of widgeon grass were found in 108 gizzards, and 
fragments of the leaves were identified from three. Seeds of eelgrass 
were present in 3 stomachs, bushy pondweed in 27, and horned pond- 
weed in 10. One of the latter stomachs contained more than 1,300 
~ seeds. 
GRASSES (GRAMINEAE), 11 PER CENT. 
Kighteen species of grass seeds were identified from the birds . 
examined, and unidentified grass seeds were taken from 19 stomachs. 
Those of the genus Panicum were most commonly eaten, being. 
_ found in 59 gizzards, often constituting a large proportion of the con- 
tents, and reaching as high as two or three thousand in number. 
Another favorite seed was that of barnyard grass, or wild millet 
(Echinochloa crus-galli), which was found in 14 stomachs, and usually 
formed the bulk of the food whenever it oecurred. One duck 
taken in Louisiana in January had eaten 6,000 seeds of jungle rice 
(Echinochloa colona), both the stomach and gullet being crammed 
full. Other grass seeds eaten by this teal were wild rice (Zizamia 
palustris), taken by 18 birds; cut-grass (Zizaniopsis miliacea), by 8; 
foxtail grasses (Chaetochloa glauca and other species), 9; and Monan- 
thochloé littoralis, 16. A few kernels of corn had been taken by one 
bird, and rice by 21. However, all these ducks were collected during 
the winter months, and the rice and corn were undoubtedly waste 
orain. | 
SMARTWEEDS (POLYGONACEAE), 5.25 PER CENT. 
Next in order of importance in the food of the green-winged teal 
come the smartweeds, which form one of the principal items of food 
of a great many birds. Thirteen species of smartweed were iden- 
tified, the most important being water smartweed (Polygonum 
amphibium), found in 35 stomachs; dock-leaved smartweed (P. lapa- 
thifoiium), in 29; Opelousas smartweed (P. opelousanum), 14; water 
pepper (P. hydropiper), 12; and mild water pepper (P. hydropiper- 
odes), 10. The other smartweeds were found in only a few stomachs 
each, and those taken from 22 other birds were not identified. One 
