Platk XXI. — Acer platanoidcs Injured in Winter of 1909-10. 



Section taken 10 cm. above that on Plate XX. Specimen kept in museum from 

 November. 1910, to July, 1912; " heart-rot " progressed; numerous Cytospora pycnidia 

 found on old dead bark at left, between 3 and 6. 



(Cut and photographed July 3, 1912.) 



