ANDREWS & BEALS: GRowTH oF ZEA Mays 99 
moist earth to a depth of about two decimeters. A young Zea 
Mays plant was placed in the soil and melted paraffine was poured 
over the surface after placing a small short paper cylinder around the 
plant. The paraffine caused all the air from the aérating apparatus 
to come out around the plant and not escape around the sides of 
the bottle or elsewhere before coming in contact with the roots. 
The bottle was supported on a ring-stand and the small glass 
tube attached to the aérating apparatus. The apparatus offered 
practically no resistance to the air supply as was shown by a 

Fic. 4. Fic. 5. 
Fic. Part of a cross section of a root of Zea Mays grown in an aérated water 
culture: Fic. 5. Part of a similar section of a root from a non-aérated water 
culture. 
manometer. A control plant was planted in a pot and set on the 
bench near by. The aérated plant in this case made almost as 
great a gain over the non-aérated as the ones so treated in the 
water cultures, showing that the increase was due to the presence 
of a greater amount of air. All the other conditions except that 
of aération were the same for both specimens in this experiment. 
SUMMARY 
1. The best length of time for soaking the grains of Zea Mays 
used in these experiments was 12 hours. 
