ELEVEN IMPORTANT WTI.D-IH'C K FOODS. 
15 
than I 1 percenl of (heir food. The 
wigeoiij a species which prefers foli- 
age to theseeds and roots of aquatic 
plants, sometimes visits salt water 
to feed upon this plant. Five of 
these birds taken at SoutH Island, 
South Carolina, in February, had 
made one-fourth of their meal of 
the leaves of eel-grass. 
DESCRIPTION OF PLANT. 
Eel-grass {Zostera marina) con- 
sists of bunches of long tapelike 
leaves which rise from a jointed 
fibrous-rooted creeping stem (fig. 
13). The leaves bear a strong 
superficial resemblance to those of 
wild celery, but they are rarely 
more than a fourth of an inch wide, 
while those of wild celery are seldom 
as narrow. The leaf of eel-grass, 
furthermore, is tougher and more 
leathery than that of wild celery. 
When a mature leaf is torn across, 
numerous white fibers may be seen 
at the broken ends. Wild celery 
lacks these. The color of eel-grass 
leaves is olive or dark green, that 
of wild celery clear light green. 1 
The leaves grow in small bundles 
from the end of the rootstock or its 
branches, and may reach a length 
of 6 feet. The rootstocks, which 
usually are reddish, have joints 
about every half inch, at which 
they are easily broken. The num- 
erous fibrous roots spring from 
these joints. Seeds of eel-grass are 
formed in sheaths alongside the 
leaves. They are about one-eighth 
of an inch in length, are placed end 
to end, and are barrel-shaped, with 
the surface conspicuously longi- 
Fig. 13.— Eel-grass. 
1 Under the microscope the leaves of these two plants are very unlike. The chlorophyll granules of 
Zostera are arranged in regular longitudinal rows, and the edge of the leaf is smooth. The chlorophyll 
granules of Vallisneria, on the contrary, are irregularly arranged and the edge of the leaf is sparingly beset 
with minute teeth. 
