PLATE i 2 i 
A. —-Alfalfa seedlings showing the effect of a short day on the growth of different 
varieties. Seed was sown in the greenhouse January 20, and seedlings were exposed 
to light from 9 a. m. to 4 p. m. Photographed March 22, 1921. 
B. ~Equipment used in determining the effect of different lengths of day on the 
seedling characters of alfalfa varieties. 
