6 The Colorado Experiment Station 
of vitality. Another contrast along the same line, was in regard to 
the frost resistance of the green growing plants; on April 26, 1908, 
the weather dropped to 22 degrees of temperature. 
The alfalfa in the nursery plats, a foot in height, was frozen 
stiff, but when the sun thawed them out, some plants were excep¬ 
tionally free from injury; the light colored foliage , seemingly to 
have suffered most. 
The past season, the temperature dropped to 18 degrees, on the 
last of April, and the alfalfa was again severely frozen back, and 
with the same results, of a contrast in resistence, but not uniformly 
in the same plants as the year before, but the dark green colored 
plants, were the most frost resistant. As a variety, the Turkestan 
plats, were the least injured; two plants from a plat of Turkestan 
Plate III. Contrast of Stooling Habits 
alfalfa, U. S. P. I. No. 18,425, show marked contrast in this trait. 
Several plants showing frost resistance have produced seed, 
which has been secured for future testing for this feature. 
One of the most valuable qualities in the alfalfa plant, is its 
habit of stooling, and its power to push out growth for three to 
four crops of hay a year, almost indefinitely; the nursery plats hav¬ 
ing been thinned to single plants twenty inches apart each way, gave 
