Bui. 1239, U. S. Dept. of Agriculture. 
Plate V. 
Fig. I. — A Culture of Wheat and Bunt on Sterilized Soil. 
The smut spores and wheat were sown under conditions as nearly aseptic as possible 
The growth of the fungus was greatly facilitated by allowing free air to enter by lifting 
tbe cover of the Petri dish at one side. The culture was incubated for eight days at an 
average temperature of 12° C. 
Fig. 2. — Effect of Mechanical Injury of the Seed Coat and Embryo 
on the Germination of Untreated Wheat Kernels. 
The lot on the right represents hand-threshed grain; that on the left shows machine-threshed 
grain Both lots were germinated in a moist chamber under identical conditions. 
