322 The Principles of Fruit -growing. 



show color. In the spring of 1897, some observa- 

 tions were made upon this point at Cornell. Buds 

 of apricots, peaches, plums and pears (as shown in 

 Fig. 53) had swollen to three or four times their 

 normal size. The pink color of the apricot buds was 

 distinctly visible, and the tips of the anthers could 

 be seen in the Japan plums by looking down squarely 

 upon the buds. In this condition, the buds endured 

 with no injury the following temperatures, as taken 

 by self -registering thermometers hung in the trees 

 (very light snow on the ground and a wind blowing 

 all night): 



Lowest temperature. 



April 20, Apricot, peach, Japan plum, pear 18 



April 21, Apricot, peach, pear 19 



Japan plum 18 



It will be seen that these buds endured 14 degrees 

 of frost without injury. Upon the coldest morning, 

 the buds were stiff from freezing, and in some in- 

 stances the backs and tips of some of the petals were 

 permanently discolored. The buds swelled with the 

 freezing, but returned to their previous size when 

 thawed out, but they looked as if withered for several 

 days, or until active expansion began. It is very 

 probable that buds cannot endure this degree of cold 

 further south. 



Injuries to flowers and growing parts. When the 

 flowers have fully expanded, a comparatively light 

 frost will destroy them. This is shown in the fact 

 that a very slight elevation in a blackberry or straw- 



