EXPERIMENT STATION BULLETINS. 



359 



Fig. 12.— Pear leaves affected with tiie leaf spot fungus. (Original.) 





^->^' .^ 



]Fie. 13. — Microscopic structure of the leaf spot disease of pear. A, portion of a section through a 



- leaf spot, showing e, e, epidermis of the leaf; p, palisade cells of leaf; sp. spongy parenchyma of 



leaf; a, a, spore case (pycnidium), giving out spores, b; B, spores highly magnified. (Original.) 



