PROGRESS IN AGRICULTURAL SCIENCE. 



495 



ent conditions. The pots of clover and lucern were left for a 

 second year's growth, and their roots could not, therefore, be ex- 

 amined. A photograph of the four pots of peas was made October 

 22d (a copy of which is given in Fig. 1), and the plants were taken 

 up for examination October 23d and 24th. 



Fig. 2. Vetches. 



The relative growth and development of the plants in the dif- 

 ferent pots are clearly shown in the photograph. "Unlike the 

 result obtained in pot 1 in 1888, with the impure and non-sterilized 

 sand, the plants in the purer and sterilized quartz sand (pot 1, 



