14 



N. H. AGR. EXPERIMENT STATION. 



[Bulletin 157 



sions are somewhat hemispherical in shape. As they continue 

 to develop they become more highly colored than the smTound- 



Fig. 15.— Bitter 1 



n Streaks in the flesh of the apple. 



ing portions and later take on various shades of brown. At first 

 this coloration shoAvs thru from rather deeply seated tissue, 



but later the surface 

 tissue also becomes a 

 dark brown. As the 

 disease advances, the 

 spots situated near 

 each other often be- 

 come confluent, devel- 

 oping into one large 

 spot or pit. The pro- 

 nounced depressions 

 in the later stages of 

 this disease are char- 

 acterized much better 

 by the term 'pit than 

 by that of spot. 



In late stages of the disease numerous spots of brown tissue 

 are found in the flesh of the apple (Fig. 15). Closer study shows 



Fig. 16." 



-A sketch of a portion of the vascular system 

 of an apple. 



