254 AGRICULTURAL EXPERIMENT STATION. [Jan. 



degree, well qualified for that purpose on account of its fitness 

 to secure largely its nitrogen from the elementary nitrogen 

 of the air by the aid of bacterial action. The photographs 

 of the roots of several prominent leguminous forage plants, 

 which accompany this chapter, show the swellings (tuber- 

 cules) due to the bacterial action, — summer vetch, blue 

 lupine, horse bean, serradella. 



The following table may serve as an illustration of the 

 relative economical value of various prominent fodder and 

 forage crops. 



The manurial value of the various crops mentioned depends 

 for obvious reasons on the temporary current prices of their 

 fertilizing constituents in the general market of commercial 

 fertilizers. 



