96 



PHYSIOLOGICAL ACTIVITIES 



Nucleiri of plant 

 'cells 



comx,o\nds^P'»<-f^'">^^^V 



Phosphates in the soil 



Fig. 67. — Diagram to illustrate the circulation of phosphorus through the 

 agency of bacteria. 



Fat^nd 

 various Ocowijjounds 



Ant'mats 



I V 



Animal ^^ 

 \reanitation 



Carbqhydrati 

 f ah and'' 

 other C chmpounds 



(h^een 

 piamU^ 



DecoflwositioTi 

 ^ \bacteria 



Various 



4 



compounds 

 cvcniually 



Fig. 68. — Diagram to illustrate the circulation of carbon through the 

 agency of bacteria. 



Dead aniprhl protein Dec^position bacteria 



^^Anrtfnal wa^t^ 

 i — ' urea, etg^'' 



^plant protein 



■Free X taken 

 up by free living 

 _N absorbers and 

 'root tubercle bacteria 



Nitrates in soil 



Fig. 69. — Diagram to illustrate the circulation of nitrogen through the 

 agency of bacteria. 



