l8 
CAROLINE RUMBOLD 
records for that month. The amount of rainfall^ is not recorded in the dia- 
gram, because it was noticed that the number of inches of rain which fell 
on the hill was not so influential in so far as the injections were concerned as 
was the number of rainy days.® 
The diagram shows the considerable capacity of the chestnut tree for 
absorbing chemical solutions. 
The mean amount absorbed by a tree per day in a 7-day-long injection, 
was in April 103 cc; in May 255 cc; June 299 cc; July 201 cc; Augiist 
229 cc; September 224 cc; and in October 178 cc 
Comparing the records of the intake of the trees with the weather 
records, it can be seen that the amount of intake is dependent on the stage of 
development of the trees, which in turn is dependent on the periodic change 
of weather during the season. The greater the capacity for transpiration, 
the larger the initial amount of intake. The irregularities of the curves are 
due to transient changes of weather modified in turn by the changing 
capacity for transpiration. 
From these records of 191 3, it appears that the most favorable month 
for injection of chestnut trees, so far as rate of intake is concerned, was 
June; after this month came, in rank, July, May, August, September, 
October, and April. 
Summary 
A compilation of the records of injections made in 156 Paragon chest- 
nut trees during the growing season of 191 3 shows that the trees possessed 
a considerable capacity for absorbing solutions of substances. 
June was the best month for injection in so far as rate of intake was 
concerned, then came July, May, August, September, October, and April. 
The rate of intake varied more in April, May, and June than in the summer 
and autumn months. 
Solutions of organic compounds went into the trees more readily than 
solutions of inorganic compounds, the "true solutions" more readily than 
the colloidal. 
Injected solutions, with a very few exceptions, were absorbed more 
readily than injected water. 
The more concentrated the solutions of chemicals were, the more readily 
they were absorbed by the trees. 
The effects of the injections here described upon the trees and upon 
Endothia parasitica will be discussed in a later paper. 
Bureau of Plant Industry, 
U. S. Department of Agriculture, 
Washington, D. C. 
* The rainfall during the period of injection work was 24.7 inches. 
^ For example, in July only 3.1 inches of rain fell, but there were 13 rainy days, the 
amount of solution absorbed per tree per day dropped during July to 201 cc. In May 4.5 
inches of rain fell, with 7 rainy days; the absorption per tree per day was 255 cc. In 
August 5.8 inches of rain fell with 6 rainy days, and the absorption per tree was 229 cc. 
per day. 
