HAIL INJURY ON FOREST TREES.* 
Frank J. PHILLIps. 
Among the minor injuries to which forest trees are 
exposed that of hail storms is one of the most interesting. 
The total amount of primary damage resulting from such 
storms is always localized sharply and while this damage 
may be temporarily great so far as the locality is con- 
cerned, it is not ordinarily severe for a whole region or 
for a whole state even for a series of years. Within the 
limits of individual storms, forest growth as a whole is 
more immune from serious effects than almost any other 
crop with the possible exception of the short, non-culti- 
vated grasses. Whole crops of fruit and vegetables are 
often entirely ruined while forest trees usually escape 
with varying amounts of defoliation, laceration of the 
bark and cambium, and the occasional destruction of 
young trees or sprouts. Many of the European texts con- 
sider this injury limitedly and one authority! on hail 
reports storms which were severe enough to remove 
branches two inches in diameter. 
No other region in the United States presents as good 
a field for such an investigation as does the middle west. 
A large number of hail storms occur in adjoining states 
but the states of the Plains may be rightly called the 
hail storm center. Missouri and Nebraska have been 
selected as good examples for this region. In both these 
states hail is a typical late spring and summer phenome- 
non, although such storms do occur in March, October and 
November in Missouri. Hail has been reported during 
the winter months, but this is probably pellets of snow 
or soft hail without crystalline structure, the same as the 
‘‘Graupeln’’ of Germany. 
In Missouri? during April and May, particularly the 
latter month, hail accompanies almost every thunder- 
‘ * Ne iy by title to the Academy of Science of St. Louis, Decem- 
er 20, ; 
1 Qn Hail. R. Russell. 1898. ? Information supplied by George Reeder, 
Section Director, U. S. Weather Bureau. 
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