98 
AMERICAN JOURNAL OF BOTANY 
[Vol. 9. 
Summary 
By means of a thermo-electrical method the extent of undercooling of 
Elberta and Greensboro fruit buds exposed to the low temperatures of 
freezing mixtures was determined. 
The data obtained indicate an increase in the tenderness of these buds 
with the approach of spring, and that just before the petals opened the 
buds of the Greensboro variety withstood a greater undercooling than 
those of the Elberta. 
Other data obtained indicate that wet buds freeze at a higher tem- 
perature than dry buds. A period of cold weather immediately following 
a rain is thus apparently more dangerous to fruit buds of the peach than 
cold weather alone. 
Laboratory of Plant Physiology, 
University of Maryland Agricultural Experiment Station 
