Bul. 153, U. S. Dept. of Agriculture. 
PLATE IV. 
Fig. 2.—NORWAY AND WHITE PINE IN MIXTURE, NORTHEASTERN IOWA, 43 YEARS OLD. 
Fic. 1.—SILVER MAPLE GROVE, lOWA, SHOWING GOOD FOREST 
ORIGINAL SPACING 1 BY 6 FEET. 
FLOOR CONDITIONS AND RATHER TYPICAL CROOKED GROWTH 
OF THE SPECIES IN THIS REGION. 
