26 MANUAL OF FRUIT DISEASES 



It has, beyond reasonable doubt, been demonstrated by means 

 of the X-rays that the disease develops internally before there 

 are any external signs of it. The first outward symptom of the 

 disease is the appearance of slightly sunken spots here and 

 there over the surface, usually most numerous toward the blos- 

 som-end (Fig. 7). These spots or pits tend to a circular form 

 and vary from mere dots to depressions measuring a quarter of 

 an inch or more in diameter. They look like hail or sand 

 bruises (Fig. 7). On a red variety the color is at first darker 

 red, while on a green variety the spots are darker green. Finally 

 the depressed areas are brown. As the fruits mature the pits 

 become more numerous and deeper, but the skin covering them 

 is not broken nor ruptured in any way. Another form of the 

 disease is found in what is known in the western United States 

 as hollow-apple. This form is sometimes called confluent 

 bitter-pit or crinkle because the upper surface of the fruit 

 develops rough folds giving it a crinkled appearance. 



If an affected apple is cut open, an area of the flesh directly 

 beneath a pit is found to be dead, brown, dry and spongy, or 

 corky. On account of these characters various names have 

 arisen : dry-rot, apple brown-spot, leige (cork disease), and 

 others. Throughout the pulp of the apple there are usually 

 found brown streaks or spots of dry, spongy flesh which do not 

 extend to the surface of the apple, and which are not connected 

 with the surface lesions. Where the pits and internal brown 

 spots are numerous the apple may have a bitter taste, whence 

 the name bitter-pit. 



There are many appearances similar to, or mistaken for, 

 bitter-pit. The apple is subject to several fruit-spot diseases 

 some of which may be regarded as identical with stippen by 

 the casual observer. The New England fruit-spot is distin- 

 guished from stippen by its spots being decidedly less 

 sunken, and by the lack of semblance to a bruise. In the 

 fruit-spot one or more black pimples develop on the affected 



