200 THE PRINCIPLES OF AGRICULTURE 



small opportunity is afforded him to destroy the less desirable 

 plants, that the more desirable ones may have better conditions. 



333a. A sprig of alfalfa is shown in Fig. 82. It has small 

 blue flowers in little clusters, and leaves of three leaflets. It is 

 grown somewhat in the East, but it is most useful in the dry 

 regions of the Plains and westward. 



335a. All the plants mentioned in this chapter should be 

 known to the pupil. In some schools, herbarium specimens 

 m^y be made of them. It is interesting and useful to collect 

 seeds of farm and garden plants. The school house may very 

 profitably contain a cabinet of seeds. Useful bottles are the 

 "specimen tubes" sold by wholesale druggists and natural -history 

 stores. One is shown in Fig. 83. It is % inch in diametf^r and 

 3 inches high, and can be bought, without the corks, for about 

 30 cents per dozen. 



For references on grasses and forage plants, consult Vol. II, 

 Cyclopedia of American Agriculture; Hunt's "Forage and Fiber 

 Crops in America;" Voorhees' "Forage Crops;" Spillman's " Farm 

 Grasses of the United States." For the cereals, see Hunt's 

 "Cereals in America." 



