268 
PHARMACEUTICAL BOTANY 
Order 2.— Uredinales, the rusts. Obligate parasites possessing 
a septated branched mycelium which ramifies through the inter- 
Fig. 139.—Smut boil of Ustilago zece on ear of corn, developed from one in¬ 
fected kernel. (After Jackson, F. S., Bull. 83, Del. Coll. Agric. Exper. Stal., 
December, 1908.) 
cellular-air-spaces of the host and sends haustoria into the cell 
cavities. The different stages of their life cycle are either restricted 
