ELEVEN IMPORTANT WILD-DUCK FOODS. 



15 



than 1 1 per cent of their food. The 

 wigeon, a species which prefers foli- 

 age to the seeds 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. 



