Brooks : The Fruit Spot of apples 425 







sap partially accounted for the differences in the susceptibility of 

 different varieties. 



Zschokke (6) presented a detailed report in regard to the 

 structure of the epidermis in core-fruits with special reference to 

 the part it plays in determining their keeping quality. His de- 

 scription of the " Stippen " and his conclusions in regard to it are 

 almost identical with those of Wortmann. 



In Australia a disease supposed to be identical with the " Stip- 

 pen " is described by Cobb (7) as Brown or Bitter Pit. 



Craig (8) described a similar disease occurring in Canada as 

 the Dry Rot of the apple. He found that sixty different varieties 

 of apples were susceptible, but that the Baldwins were affected 

 most seriously. 



In the United States the spotting of apples has been repeatedly 

 described and variously named. Selby (9) reported a disease of 

 Northern Spies and other varieties which produced small brown 

 spots just beneath the skin of the apple and which usually did 

 not extend to any great depth into the tissue. He found no fun- 

 gus present and considered it a breaking down of cells brought 

 about by seasonal conditions. 



Jones (10) described the " Brown Spot of the Baldwin Apple " 

 as producing brown sunken spots the size of a pea or larger on 

 the surface of the apple. The flesh underneath these spots showed 

 a brown discoloration for an eighth of an inch or more in depth. 

 The discolored portion was quite bitter to the taste. Specimens 

 of the diseased fruit placed in a moist chamber soon developed 

 small grayish pustules at or near the center of the spot, the pus- 

 tule being from a sixteenth to an eiehth of an inch in diameter. 



who 



was 



Specimens of the fungus were sent to J. B. Ellis for identification 



reported that it was probably Dothidea pomigena Schw. 

 Lat er, Jones ( 1 1 ) stated that the fungus occurring in the spots 

 quite different from the above species. In most cases, espe- 

 °' ally m the autumn and early winter, no fungus was detected in 

 * e browned tissue. When it was present it was quite obscure. 

 e fun S u s was not identified because of inability to secure satis- 

 ac tory fruiting specimens. He considered the fungus a sapro- 

 P yte and of minor importance so far as the disease was con- 

 [ ernedl In the later publication the spotting was given the fol- 

 low,n g description : 



