THE BLOOD OF TREES. 53 
feet from the ground, and the development of leaf and 
flower buds is not usually affected by any mechanical 
pressure of the sap forced into them from below, their 
vitality is stimulated to activity by the genial influence 
of the sun, and their growth is, in its beginning, caused 
by the assimilation of organic substances accumulated 
during the preceding season of vegetation. 
These experiments and observations are not final and 
conclusive in several respects, but they may be looked 
upon as having opened the door to an almost exhaust- 
less subject of which the world needs information. I 
hope they will be read with interest by the most indif- 
ferent, and will be carefully studied in all their relations 
to the natural world by those who delight in such re- 
searches. 
