18 CONTROL OF THE CHESTNUT BARK DISEASE. 
girdling or partly girdling the young tree, may be seen; this is very 
characteristic, but is so prominent a symptom that it may be noticed 
at the nursery, and presumably trees so affected will not be shipped. 
Tf infected trees are set out they develop the disease with its char- 
acteristic symptoms the following spring. But on account of their 
small size such trees are girdled and die before the end of the sum- 
mer, often in two or three weeks. Meanwhile they are spreading 
the disease to neighboring orchard and forest trees. Orchardists 
and nurserymen purchasing chestnut trees are therefore warned to 
watch them closely during the first season, no matter how rigidly 
they may have been inspected. 
INDIVIDUAL TREATMENT OF DISEASED TREES. 
Where valuable ornamental, shade, or orchard chestnut trees be- 
come infected in one or more spots, the life and usefulness of such 
trees can be prolonged for several or for many vears, depending 
largely upon the thoroughness with which the recommendations 
herein given for cutting out the diseased areas (lesions) are carried 
out. These recommendations are based upon the results of extensive 
experiments with hundreds of lesions during the past four years. 
These experiments were performed for the most part by the junior 
writer. 
The essentials for the work are a gouge, a mallet, a pruning knife, 
a pot of coal tar, and a paint brush. In the case of a tall tree a 
ladder or rope, or both, may be necessary, but under no circumstances 
should tree climbers be used, as they cause wounds which are very 
favorable places for infection. Sometimes an ax, a saw, and a long- 
handled tree pruner are convenient auxiliary instruments, though 
practically all the cutting recommended can be done with a gouge 
with a cutting edge of 1 or 14 inches. All cutting instruments 
should be kept very sharp, so that a clean and smooth cut may be 
made at all times. 
By cutting with the gouge into a diseased area a characteristically 
discolored and mottled middle and inner bark is revealed. All of 
this diseased bark should be carefully cut out for xt least an inch 
beyond the discolored area if the size of the branch will allow it. 
This bark should be collected in a bag or basket and burned. If the 
cutting is likely to result in the removal of the bark for much more 
than half the circumference of the branch or trunk, it will probably 
be better to cut off the entire limb or to cut down the tree, as the 
case may be, unless there is some special reason for attempting to 
save the limb or tree. The fungus usually, though not always, de- 
velops most vigorously in the inner bark next to the wood. When 
this is the case, not only all the diseased bark and an inch of healthy 
bark around it must be removed, but at least two or three annual 
layers of wood beneath the diseased bark must also be gouged out. 
Special care should be taken to avoid loosening the healthy bark at 
467 
