PLATE 55 



Pninus leaves from inoculation experiments, illustrating various degrees of infec- 

 tion, as recorded in Tables I to IX: 



A.— P. mahaleb, infected by a strain of Coccomyces from P. serotina. 



B. — P. serotina, infected by a strain from P. serotina. 



C. — P. cerasus, infected by a strain from P. avium. 



D. — P. pennsylvanica, infected by a strain from P. pennsylvanica. 



Figures A, B, C, and D would be represented in the tables by the numbers 2,3,4, 

 and 5, respectively. B approaches the maximum of 3, while C approaches the mini- 

 mum of 4 (see footnote c, Table I). 



