94 CHESTNUT TREE BLIGHT. 
racticable at present to apply any individual method of treatment 
ts forest trees 4 the indavideal tee is not worth it, and will not be 
for many years. Therefore, so far as the chestnut forests are con- 
cerned, we do not need to regret particularly that no individual 
treatment has yet been discovered that is entirely effective. 
Fortunately, however, there is a method of dealing with the situa- 
tion which is applicable to the country as a whole and which, so 
far as tested, is practicable. Early in the course of the writers’ 
investigations it became evident that the disease advances but slowly 
in'a solid line, but instead spreads from isolated centers of infec- 
tion, often many miles in advance of the main line of disease. That 
such is the case is evident from a glance at figure 2. It therefore 
seemed probable that if these advance infections could be located 
at a reasonably early stage they could be eliminated at relatively 
little expense, thus preventing further spread from these points at 
least. Accordingly, the country within approximately 35 miles 
of Washington, D. C., was chosen in the fall of 1908 as preliminary 
territory in which to test this method of control. This section has 
since been gone over ges thoroughly once a year. As will be seen 
by figure 2, 14 points of infection were-located, and the infected 
trees destroyed. Most of this work was done by the senior writer. 
The largest infection was a group of nursery trees that had been 
imported from New Jersey; the smallest, a single lesion on a small 
branch of a large forest tree. In one case 11 forest trees in a group 
were infected, the original infection having been two trees, dating 
apparently from as early as 1907. Up to the present time (June, 
1911) the disease has not reappeared at any point where eliminated 
and the country within a dia of approximately 35 miles from 
Washington is apparently free from the bark disease, although new 
infections must be looked for as long as the disease remains elsewhere 
unchecked. It is therefore believed that this method of attack will 
rove equally practicable in other localities, and if carried out on a 
arge scale will result ultimately in the control of the bark disease. 
LEGAL CONSIDERATIONS. 
In ca g such a scheme of control into effect on a large scale, 
however, legal difficulties are at once encountered. The bark dis- 
ease threatens the extinction of the chestnut throughout its range. 
As it has already been found in at least 10 States and the District of 
Columbia, it is essentially a national issue, but there is no law 
whereby the Federal Government can attempt to cope with the 
rap Each State must act on its own initiative and control 
the disease or let it go as its officers and legislative bodies see fit. 
Herein lies one of the most serious aspects oft the matter; for if one 
State elects to undertake control of the disease it will be seriously 
handicapped if neighboring States do not. Any method of elimina- 
tion, isolation, or quarantine in dealing with any disease of plants, 
domestic animals, or human beings necessitates general cooperation. 
It is not practicable to try to control the bark disease solely by the 
cooperation of individual owners of chestnut woodland, since a sin- 
gle indifferent or obstinate person can nullify the efforts of an entire 
community. The control of the chestnut bark disease must there- 
fore be undertaken by the separate States under special legislation. 
