378 
work. And as a source of tannic acid 
it was unsurpassed. Indeed, by the 
time the blight had moved from New 
York to Virginia, it was estimated that 
the loss in timber alone was in excess 
of $25,000,000. 
The tragic part about our attitude 
toward destructive diseases and in- 
sects is that, because they work silently 
and undramatically, we find it difficult 
to become greatly concerned until 
their deadly work is done. Then we 
lick our wounds, total up our losses, 
and indignantly ask each other, 
*“Couldn’t it have been prevented?” 
We are still asking this about the 
chestnut disaster. The answer, how- 
ever, is likely to be lost somewhere 
in this pattern of reasoning: at the 
time of the outbreak there was little 
understanding of plant diseases; much 
valuable time was lost after the out- 
break in searching out the factors 
responsible for the epidemic and in 
vacillation and acrimonious debate; 
the disease, once established, spread 
like lightning; and finally the eastern 
woodlands became so thoroughly per- 
meated that no human control was 
practical. 
When Forester Merkel examined 
the trees dying in New York’s Zoo- 
logical Park, he found interesting 
marks on their trunks and branches. 
A sunken area of dried-out bark, a 
sort of canker, was always present. 
On the surface of the cankers he fre- 
quently saw thousands of yellowish 
pin-point projections. He immedi- 
ately sent samples of this material 
to the Department of Agriculture, 
which reported that the bark was 
riddled with a fungus, that the yellow 
pin points were fruiting bodies, con- 
taining millions of spores. When these 
spores were released from the fruiting 
bodies they could be blown miles to 
infect other chestnut trees. 
This particular fungus was a deadly 
parasite. Only one infinitesimal spore 
lodged in a fissure or slight abrasion of 
the protective bark of the chestnut 
could send out minute rows of rootlike 
strands which would expand into a 
ANNUAL REPORT SMITHSONIAN INSTITUTION, 1948 
fan-shaped, white or buff-colored 
mass. The ‘fan’? would penetrate the 
trunk of the tree, pushing its way into 
the sapwood. Eventually, the fungus 
would destroy the cells growing next 
to the tubular conductors through 
which water ascends from the tree’s 
roots to its leaves, thus cutting off the 
tree’s water supply. The net result of 
this interior strangulation was iden- 
tical with the effect of girdling a tree 
trunk with knife or ax. 
Despite these revelations regarding 
the disease, protective action was in- 
effective. Merkel’s attempt to control 
the spread of the fungus with Bor- 
deaux, a copper-sulfate spray which 
the French had used _ successfully 
in controlling a fungus disease of 
grape, was a complete failure. So, 
with nothing to block its progress, the 
blight, by 1911, had spread from New 
York to New Hampshire, Connecticut, 
New Jersey, Pennsylvania, West Vir- 
ginia, and Virginia. 
A number of scientists believed the 
disease would disappear of its own 
accord, but generally there was rising 
fear that it would sweep down through 
the extensive chestnut forests of the 
South. One of the first real stands 
made against its march was in Penn- 
sylvania where a Chestnut Tree Blight 
Commission was created with $275,000 
at its disposal. Believing the blight 
controllable, the commission set about 
making investigations of practical con- 
trol measures, started research on the 
peculiarities of the blight fungus, and 
dispatched 200 scouts to locate and 
destroy infected trees. Its peak effort 
was a serious, if not desperate, attempt 
to establish a 10-mile zone across 
which, it was hoped, the blight 
organism would fail to find its way. 
Within this ‘immune belt,” as it was 
called, all chestnuts, healthy and dis- 
eased, were destroyed. 
Previous investigation of the blight 
fungus revealed that instead of one 
type of spore, as supposed, the fungus 
possessed two types. The first, called 
ascospore by the researchers, was pro- 
duced in microscopic receptacles with- 
