26 BULLETIN 862, U. S. DEPARTMENT OF AGRICULTURE. 
MISCELLANEOUS VEGETABLE FOOD, 11.95 PER CENT. 
A large number of minor items of vegetable food were classified as 
miscellaneous. Probably the largest of these consisted of plants of 
the duckweed family (Lemnaceae). Although found in only 14 
stomachs, they constituted nearly 100 per cent of the contents of 
several. Hach of three stomachs collected in Iowa in August con- - 
tained more than a thousand of the small plants of a duckweed 
(Lemna sp.). Twenty-eight other families of plants were represented, 
the most important being the aster family (Compositae), the water 
plantain family (Alismaceae), the parsley family (Umbelliferae), 
crowfoot family (Ranunculaceae), borage family (Boraginaceae), 
myrtle family (Myricaceae), rose family (Rosaceae), hornwort family 
(Ceratophyllaceae), and the vervain family (Verbenaceae). 
Anima Foon. 
Animal matter constitutes 29.47 per cent of the total food of the 
blue-winged teal, which is more than three times the percentage of 
animal food eaten by the green-wing. Over half of this (16.82 per 
cent) is mollusks, the remainder being made up of insects, 10.41 per 
cent; crustaceans, 1.93, and miscellaneous, 0.31 per cent. 
MOLLUSKS (MOLLUSCA), 16.82 PER CENT. 
The ate part of the shellfish found in the stomachs some! 
probably consisted of snails, although small bivalves also had been 
commonly taken, and in a senor of cases the shells had been so 
thoroughly crushed by the powerful gizzards of the ducks as to 
make it impracticable to distinguish between the fragments of 
bivalves and univalves. However, 15 species of the latter were 
identified, and 2 of the former. Unidentified univalve shells were 
found in 31 stomachs and unidentified bivalves in 2, while fragments 
of mollusk shells taken from 106 stomachs were not classified. The 
full stomach of a duck collected in an Iowa swamp in August, 1907, 
contained thousands of snail eggs, amounting to 54 per cent of Le 
contents. 
INSECTS (INSECTA), 10.41 PER CENT. 
The items of insect food of the blue-winged teal, in the order of 
their importance, are caddis larvae (together with their cases), 
beetles and their larvae, dragonflies and damselflies (chiefly in the 
nymph stage), bugs, flies (chiefly larvae), and a small percentage of 
miscellaneous insects. 
The larvae of caddisflies (Phryganoidea) or their cases were found in 
37 stomachs, and amounted to 4.5 per cent of the total food. The 
greater part of these were found in.a series of stomachs collected in 
Florida, some of which were over half filled with the fragments of 
caddis cases. 
