BOX EXPERIMENTS WITH PHOSPHORIC ACID. 69 



As very few insects were present during the growth of the 

 plants, the fruiting, as might have been expected, was very 

 irregular. As soon as the plants seemed to have attained their 

 maximum development, they were harvested, dried, weighed, 

 and the total amount of dry matter determined for each crop 

 grown. In the diagrams that follow the average production for 

 a single period is shown, the heavy lines representing the relative 

 weights of dry matter, and the last column the weights in grams. 



