Nutrition. 



99 



A B 



F'&- 73— -^1 root system of pea with tubercles; B, root system of lucerne with 

 tubercles. After Belzung. 



organic matter from the bread in much the same manner as 

 the root-hairs absorb mineral solutions from the soil. 



VI 



Fig. 74,— Bacterioidal organism in tubercles of leguminous plants. /, filaments 

 in parenchyma cells ; //, formation of bacterioids from filaments ; ///, bacterioids 

 in cells ; IV, various forms of bacterioids ; K, section of a tubercle ; VI, cell con- 

 taining bacterioids and fragments of filaments. 



