26 THE RELATION OF SPARROWS TO AGRICULTURE. 
English sparrows are also useful destroyers of weed seed. Thou- 
sands may be seen every autumn on the lawns of the Department of 
Agriculture feeding on crab-grass (Panicum sanguinale) and yard- 
grass (Eleusine indica), two weeds thai crowd oul good turf-making 
grasses. They deserve further credil for their good work in destroy- 
ing seed of the dandelion (Taraxacum taraxacum), which is a prolific 
weed throughout the United States, especially in lawns and pastures, 
and is also troublesome in cemeteries. In the public parks of Wash- 
ington, I>. C, the birds ea1 these seeds from the middle of March 
until tin' middle of August, but chiefly in April and the fust half of 
May. when the lawns are full of dandelions. After the yellow bloom 
has disappeared the head closes and a downy tuft appears at the 
upper end; in this stage it is mosl frequently attacked by the English 
sparrow. The bird removes several long scales of the inner involucre 
b\ a clean cut close to the receptacle or base of the head, thus expos- 
ing the plumed seeds orakenes. It seizes a mouthful of these akenes, 
lops off tin' plumes with its bill, and swallows the s<mm!s. In many 
cases, especially when hungry, it does not take the trouble to remove 
the plumes. Generally it drops a score of seeds in tearing open a 
head, and usually leaves a few clinging to the edge of the receptacle. 
The mutilation eaused by the bird's beak can be detected until the 
flower stalk dries ami falls. One day I examined every stalk in a rec- 
tangular space 6 feet 2 inches long by 3 feet 3 inches wide. Of the 
413 stalks collected 358 showed unmistakable marks of the sparrow's 
bill. On the next day 293 stalks were gathered from a circle 2 feet in 
diameter on the other side of the lawn, and i?7 5, or 1)3 percent, proved 
to be mutilated. These and similar observations made with varying 
results, covering several years, showed that at least three-fourths of 
the dandelions that bloom in April and .May on the Department lawns 
are mutilated by birds. In this destruction of dandelion seeds, the 
English sparrow is aided by several native birds, chiefly the song 
sparrow, the chipping sparrow, and the white-throated sparrow. So 
far as observed, the native birds usually do not cut open dandelions, 
but simply \'^v(\ on those left by the English sparrow. The song spar- 
row, however, is capable of getting out seeds alone: for one which 
was kept in captivity manipulated dandelions in precisely the same 
Way as the English sparrow. 
Besides such lawn weeds as dandelions, crab-grass, and yard-grass, 
several others, including pigeon-grass, knotweed, sedge, oxalis, and 
Chickweed, furnish food for sparrows. These plants are also trouble- 
some in other places than lawns. Knot weed {Polygonum avicuLan ) 
litters Up paths and roads and grows in spots where turf is broken; 
chickweed (Alsiru media) occurs in plowed ground-; and pigeon-grass 
( ( 'h<i tocloa glauca aid ( '. viridis), which is considered one of the worsl 
«»t wc.-ds in Minnesota, is found among many crops. The seeds of 
these weeds are eaten by the song sparrow, chipping sparrow, field 
