16 



points between (Plate 1, Fig. 15), 



Litera ture 



There are only a few references in literature to Alter- 

 naria as an enemy of the apple. Morso"^ mentions the leaves as 

 being attacked. Stakman and Rose^ of Wisconsin describe an Al- 

 ternaria on the fruit of the Wealthy apple. It causes a small 

 brown spot in some ways resembling those above described. Per- 

 sonal communication with these authors, however, proved it to be 

 different. The spot they write of is much smaller, different in 

 color, and has a more regular outline. They were able to produce 

 typical spots when the organism was inoculated on the fruit, which 

 I have not been able to accomplish, 



Longyear^ of Colorado has found Alternaria causing a 

 blossom and core rot which anters in the stamens and stigmas and 

 usually occurs in storage. These are both soft rots. Coojc and 

 Martin"* found Alternaria in the Jonathan spot, and consider it to 

 be the cause. They produced typical spots with the isolated 

 organism. However, Scott^ considers that the Jonathan Spot is 



due possibly to arsenical poisons, and Norton^ ascribes it to 



7 



gases from the cooling plants. Brooks, Fisher, and Cooley found 

 Alternaria in apples in storage. 



It is possible that all these diseases, including the 

 one above described, are caused by the same organism, a variety 



of A_j tenuis^ which has under different environmental conditions 



become changed. It is a question whether their behaving differ- 

 ently when inoculated on apples is sufficient reason for their 



