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IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 
species. They were planted early in October in sandy humus 
in the greenhouse, receiving an abundance of water. The sur- 
Fig. 64. — The upper figure seedling bur-oak with expanded leaves and 
very young leaves, stipules, also scales on stem. The lower figure chestnut oak 
( Q . acuminata), scales below on stem, full expahilod leaves and unfolding 
leaves. Photographed May 1, by Colburn. 
face was kept moist with sphagnum moss. In the course of a 
few days the acorns split near the upper apical end and the hypo- 
