178 



of the States of Maine, New Hampshire, Vermont, Alas^acliti- 

 setts, Kliode Island, Connecticut, New Yorlv, New, Jersey, Penn- 

 sylvania, Delaware, Maryland, Virginia, West Virginia, Ohio, 

 Indiana, Kentucky, Tennessee, North Carolina, South Carolina, 

 Georgia, Alabama and Mississippi are likely to become involved. 

 As the disease is spread from tree to tree by spores of the fun- 

 gus which causes it, the spread is usually rapid after a single 

 tree in a locality is infected. 



There is evidence that the spores are spread through short dis- 

 tances by rain ; through longer distances it appears possible that 

 it is spread also by birds, insects and rodents, such as squirrels. 

 The disease is carried bodily for considerable distances in tan 

 bark and in uubarked timber derived from diseased trees. It 

 is also frequently transported on diseased nursery stock. 



No method of immunizing individual trees is yet known and 

 no method of treating or curing them when once attacked is 

 certain in its results. This being the case, so far as the chestnut 

 forests are concerned, the only practicable method of dealing 

 with the situation is that of i)ronipt location of isolated centers 

 of infection in advance of the main line of the disease, coupled 

 with the pi'om])t cutting ont and destruction of such scattered 

 diseased trees. This method has been tested sufficiently to in- 

 dicate that it is practicable to control the disease where the 

 situation is effectively attacked before a general infection lias 

 resulted. In addition to this it may be found necessary to es- 

 tablish an immune zone by destroying all cliestnut trees, diseased 

 or healthh', in a l)elt ten to twenty miles wide, or possibly less, 

 in advance of the main area of infection, with a view to barring 

 its progress. A regional quarantine of chestnut products likely 

 to move from the area of complete infection to protected terri- 

 tory may be found necessary. This is now a subject of con- 

 sideration in the investigations that are under way. 



The disease having already done much damage in eastern Penn- 

 sylvania and northeastern Maryland, but not having appeared 

 to a destructive extent in the states fartlier south, it is peculiarly 

 important at this time that effort be made to stay the progress of 

 the disease before it reaches the heavily timbered chestnut arenas 

 of Maryland, West Virginia, Virginia, and the mountain regions 

 farther south. The fact that the State of Pennsylvania 1ms ;tp- 



