INTERNAL, BROWNING OF YELLOW NEWTOWN APPLE. 5 



physiological diseases, such as Jonathan spot, bitter-pit, and scald, 

 in which discolored spots may appear in the skin of the fruit. 



Plates I and II show various degrees of internal browning as it 

 appears in cross sections of Yellow Newtown apples. It will be seen 

 that internal browning may appear anywhere in the flesh of the 

 apple, either immediately around the core or farther out toward the 

 skin. Quite frequently internal browning appears only around the 

 core, the outer fleshy portion of the apple remaining normal in ap- 

 pearance. On the other hand, though less frequently, only the outer 

 flesh is involved. Usually when internal browning develops in the 

 outer fleshy portion it is accompanied by browning around the core. 

 There seems to be a tendency, however, for it to occur symmetrically 

 as regards the morphology of the fruit. In very mild cases when an 

 apple is cut crosswise only a small spot faintly tinged with brown 

 may be seen in the angle between two adjacent seed cavities, the re- 

 mainder of the cut surface appearing quite normal in color. In other 

 cases faintly browned areas may appear around the core, accom- 

 panied by one or more discolored areas of various sizes and degrees 

 of browning in the fleshy portion of the apple. Thus, all gradations 

 from normal to badly browned core areas may be accompanied by 

 equally varied conditions in the outer flesh of the fruit. 



Frequently, in mild cases, a section through the widest diameter 

 may show no internal browning, while further cutting, particularly 

 toward the stem end, may reveal traces of this discoloration. 



The fruit at picking time shows no visible indication of internal 

 browning, and it is evident that the tendency to develop this trouble 

 in storage is inherent in the fruit when it comes from the tree. Just 

 what factors or conditions of the fruit determine this tendency the 

 writers are not prepared to say, though interesting suggestions on 

 this subject will be brought out later. 



In presenting the results of these investigations it has seemed 

 undesirable and unnecessary to include the long tables of figures and 

 data that have accumulated from the work of each year. The data 

 bearing on the most important phases of the subject have been con- 

 densed and tabulated for the purpose of giving the reader a clearer 

 understanding of the results. Considerable information has been 

 accumulated on certain chemical and physiological phases of apple 

 storage as a result of investigations conducted for the purpose of 

 learning • something about the inherent differences between normal 

 apples and apples subject to or showing internal browning. Unfor- 

 tunately much of that work has contributed relatively little toward 

 an understanding of the problem in hand, but the information 

 gained is of value as an addition to our relatively meager knowledge 

 of the physiology of cold-storage fruits. 



