Fig. 3, A.—Schematic drawing of a cross section of a wheat-seedling leaf showing spongy mesophyll and vascular bundles, and absence of sclerenchymatous tissue. B.—Schematic 
drawing of a cross section of an adult wheat leaf showing vascular bundles, v , and supplementary sclerenchyma, s , These partitions divide the leaf into as many longitudinal 
segments of parenchyma 
Sept. 1, 1924 
Stripe Rust 
217 
