37S 
IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 
Russian Ooak ( Quercus Bobur var. pedunculata ) . The acorns 
were gathered on September 20, planted in the greenhouse in 
sandy humus, covered with sphagnum and kept moist. Many of 
the acorns were split at the apical end on October 4. The hypo- 
Fig. 66. — Right hand figure valley oak ( Quercus lob at a ) , fully expanded 
leaves and unfolding leaves, both branches from the same acorn. The left 
hand figure, Russian oak ( Q . Robur var. pedunculata), showing stipules, 
scales and fully formed leaves. Photographed May 1, by Colburn. 
cotyl pushed its v r ay down into the soil, increasing in length 
very rapidly. On October 18 it was two inches in length, at 
first whitish in color, becoming brownish. 
