THE CHESTNUT BARK DISEASE. 369 
for trees to be grown in the South. Resistant timber trees, as well as 
nut trees, could doubtless be produced. Many experiments along this 
line are already in progress. In the long run the results of breeding 
will probably be the most profitable outcome of the struggle against 
the bark disease. Sooner or later we must begin to breed forest trees 
systematically, and the chestnut is on many accounts a good tree to 
start with. 
INSPECTION OF DISEASED NURSERY STOCK. 
As has been indicated, diseased chestnut nursery stock in the past 
has been an important factor in the spread of the bark disease. On 
account of a well-grounded fear of this disease much less chestnut 
nursery stock is being moved now than formerly, but there is still 
enough to constitute a serious source of danger. It is therefore ob- 
vious that every State in which the chestnut grows, either naturally 
or under cultivation, should as speedily as possible pass a law 
putting the chestnut bark disease on the same footing as other 
pernicious diseases and insect pests, such as peach yellows and the 
San Jose scale, against which quarantine measures are now taken. 
Many inspectors already have the legal power to quarantine against 
the bark disease on chestnut nursery stock, and they should now take 
special care that no shipment, however small, escapes their rigid 
inspection. 
The most serious practical difficulty in inspecting nursery stock 
for this, as for other fungous diseases, lies in the fact that practically 
all State inspectors are necessarily entomologists and are usually 
not trained in recognizing the more obscure symptoms of fungous 
diseases. Nursery trees affected by the bark disease rarely show it 
prominently at the time when they are shipped; the threads of co- 
nidia or the yellow or orange pustules are rarely present, and usually 
all the inspector can find is a small, slightly depressed, dark-colored 
area of dead bark, usually near the ground, which is easily over- 
looked or mistaken for some insignificant injury. Upon cutting into 
such a spot the inner bark shows a most characteristic disorganized 
“punky” appearance quite different from that of any other bark 
injury. Occasionally a yellowish brown or reddish band or blotch, 
either girdling or partly girdling the young tree, may be seen, 
which is very characteristic. 
If infected trees are set out they develop the disease with its char- 
acteristic symptoms the following spring. On account of their small 
size such trees are girdled and die before the end of the summer. 
Meanwhile they become a source of danger 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. 
72029°—yrK 1912——24 
