RICHARD H. BOERKER
Department of Botany, University of Nebraska, Lincoln, Nebraska, UNITED STATES OF AMERICA.
The germination of seeds depends principally upon edaphic factors, hence climatic factors will receive little attention here except in so far as they condition the former. It is taken for granted that the morphological and the physiological significance of water, light and heat to plant life are too well known to require discussion here, especially since that phase of botany is fundamental in all ecological work. The water content of the soil is by all odds the most important edaphic factor in determining germination, for while other factors may condition this process to a certain extent, none but water, within certain limits, can prevent it altogether. In a synoptical manner I will briefly call to mind the significance of this master factor in germination and then briefly inquire into the important soil factors and properties that bear directly on the investigations at hand.