1242 Wisconsin Academy of Sciences, Arts, and Letters. 
EXPLANATION OF PLATE XCIIL 
Fig. 56. Cross-section of leaf showing distribution of spores and xpyce- 
lium. X460. 
Figs. 57-62. Stages in spore-formation. X2500. 
Fig. 63. Surface view of a young appressorium. 
X2500. 
