ECONOMIC CLASSIFICATION OF GRASSES 13 
liquor, the alcohol being converted into acetic acid by 
means of ferments. Besides being used for the production 
of seed, the grasses mentioned above are extensively used 
for forage, a use which will be discussed in a future chap- 
ter. Corn in one of its varieties or species, sweet corn, is 
commonly used as a vegetable, the kernels being cooked 
when in the milk stage. Other varieties are cultivated for 
ornament and for pop-corn. The pith of the stalks of 
field corn has been used for many purposes, especially 
those involving the production of pure cellulose. 
