EFFECTS ON CHESTNUTS OF SUBSTANCES INJECTED 
55 
had an injection definitely stopped the growth of a canker. No further 
inspection has been given these trees. 
Summary of Results 
This and the preceding paper® constitute a report on an attempt made 
to answer by experimentation the following questions: 
1. What substances can be injected into living chestnut trees? 
2. When can they be injected? 
3. Where does the injected material go? 
4. What is the eflfect on the tree? 
5. What is the effect on Endothia parasitica growing on the tree? 
A compilation of the records of injections made in living chestnut trees 
during the growing seasons for five years showed : 
1. That the trees possess a considerable capacity for absorbing solutions 
of substances. 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. In the dilutions used in 
these experiments, the more concentrated the solutions were, the more 
readily they were absorbed by the trees. 
2. In southeastern Pennsylvania, 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, but obviously 
was dependent upon the local weather conditions. 
3. Examination of the trees showed that the injected solutions as a 
rule passed through the vessels of the youngest annual ring of wood up and 
down the tree trunk in a zone whose width was usually but little more than 
that of the injection hole. They passed into the branches and leaves, and 
in the case of the lithium salts into the nuts. They passed into the roots. 
4. In general, the injection of the alkali metals was not detrimental 
to the trees; injection of heavy metals was detrimental; colloidal metals 
were not detrimental; organic compounds were not detrimental; water 
extract of chestnut blight canker was detrimental, healthy bark extract 
was not. The effect varied with the dilution of the solution and with the 
month in which the injection was made. Many of the bases produced 
characteristic discolorations of the leaves. Usually the visible effect of a 
solution upon a tree varied with the distance from the point of injection. 
The injections can cause the appearance of pathological xylem in the tree 
trunks. 
5. This work is not completed and the results are inconclusive. Dilute 
^ Rumbold, C. The injection of chemicals into chestnut trees. Amer. Journ. Bot. 
7: 1-20. 1920. 
