Unfortunately these species are comparatively low-growing trees and can 
therefore not replace the American chestnut as timber-producing trees. For 
many years the Division of Forest Pathology, U.S.D.A., and more recently 
the Brooklyn Botanic Garden, have been breeding these resistant orientals 
with the native American species in the hope of developing a disease-resist- 
ant stock of tall timber quality suitable for replacing the American species. 
To date more than 30 hybrid chestnut types, new to science, have been de- 
veloped, from some of which, by further breeding, it is probable that types 
desirable for reforestation can be produced. The experimental plantation 
of the Brooklyn Botanic Garden is located at the eastern end of the Sleeping 
Giant Mountain, in Hamden, Connecticut, about 10 miles north of New Haven. 
At present more than 750 young trees are growing there: more than 250 of 
these are hybrids, the rest are distributed among various species and varieties 
from Asia, Europe, and Eastern North America. 
{First CROP) 
<RISEVENTHYEAR 
FARsT YEAR’ ie LAMTHIs ano Roots 
: Supe Root CaitaawARe, Disease 
Drawn by Miss Maud H. Purdy, Staff Artist, Brooklyn Botanic Gardens. 
Fig. 2—Diagram of stages of growth and development of basal shoots from blighted chestnut trees 
Basal shoots:—Throughout the range of the chestnut young shoots are 
continually arising from the base of diseased trees or stumps, to such an ex- 
tent as to produce a widespread belief that the chestnut is “coming back”. 
The key to this situation is the fact that the roots are more resistant to the 
attack of the fungus than the trunk or branches. When the tree dies down 
to the ground, adventitious buds at the root collar produce new shoots which 
utilize the main root of the old tree, usually still healthy in certain parts, 
for their support from the soil. Soon, however, they develop their own 
roots, while in the meantime. the disease progresses further down into the 
roots of the old tree. For, although the roots are more resistant to the dis- 
ease, they are not immune. The fungus does advance into them, but it ad- 
vances more slowly. Eventually, therefore, the fungus penetrates into the 
adventitious shoot from the old diseased “mother” tree. But, meanwhile, one 
or more of the shoots may have lived 4, 5, or 6 or even more years, and, 
possessing at the start the roots of the mother tree, their growth may be re- 
