96 ANDREWS & BEALS: GROWTH OF ZEA Mays 
TABLE VI gives the height of the plants at different stages of 
growth where 100 c.c. of air per minute is used. 
After three months’ growth under as nearly normal growing 
conditions as possible, the plants were removed and the amount of 
ash ascertained. The ash of the aérated plant including the roots 
were 2.181 grams while the ash of the non-aérated plant weighed 
1.303 grams. In another experiment after two months’ growth 



Fic. 1. Non-aérated and aérated specimens of Zea Mays. 
the ash of the aérated plant (including the roots) weighed 1.855 
grams, while the non-aérated plant weighed 0.65 grams or almost 
three to one in favor of the aération. The difference is well shown 
in Fic. 1. The same experiment was performed a number of 
times, the aérated plant always showing the same marked im- 
provement over the non-aérated one. 
Another experiment, shown by Fic. 2, was performed using 
five cylinders. The air was driven through these cultures by 
means of a Bunsen Pump apparatus. The culture A received 
