diseases that laboratory tests are necessary to identify them 
unquestionably, and are both carried by insects. Dutch elm 
disease is a fungus which was introduced into this country from 
Europe between 1920 and 1930; since then it has spread from 
New York and the New England states to the Mississippi, and 
its carrier, a bark bettle, has been observed as far west as 
Nebraska. Phloem necrosis, a virus disease, was first noticed in 
1938 along the lower and central Ohio River watershed; since 
then it has spread southward and westward, and its carrier, 
a leaf-hopper, is observed in Wisconsin and in some eastern 
states. (For further information see United States Department 
of Agriculture Circulars No. 640, June 1942; No. 677, July 1943; 
and Special Circular 80, April 1949.) 
Reports of these elm plagues have alarmed America’s tree- 
lovers. But there are many causes for taking heart and for 
resisting the belief that the old tradition of the elm tree in 
America is destined to come to an end. Perhaps the most obvious 
and general of these reasons for encouragement is that the elm 
is a species which has a history of at least 60 million years. 
There are geological evidences of the elm species in early 
Tertiary rocks (i.e., formed about 60,000,000 years ago) in 
Greenland, and there is some evidence that this species existed 
even before that in the Upper Cretaceous times. Elm trees 
inhabited Europe, Western Asia and North America before the 
Glacial period (more than one million years ago.) During these 
early pre-glacial times in North America, great elm forests 
grew on the mid-continental plateau and ranged westward to the 
shores of the Pacific Ocean (cf, Charles 8. Sargent, The Silva of 
North America, vol. VII, pp. 40-1 and Frank H. Lamb, Book of 
the Broadleaf Trees, p. 232). It does not seem likely that this 
ancient tree will pass away in our or our great-grandsons’ 
lifetimes. 
Report of elm diseases seem to be exaggerated. The Dutch 
elm disease was introduced from across the Channel into 
England long before it was into the United States, and no real 
attempt was made there to stop its progress except by general 
sanitation in very limited areas. But the Forestry Commission’s 
Forest Pathologist at the Forest Research Station in Farnham, 
England wrote us recently that “‘the damage done by it (i.e., 
elm disease) has not been as catastrophic as was first expected.” 
So the English, who are noted for their understatement, at first 
exaggerated elm tree damage. The Principal Pathologist of the 
U. S. Department of Agriculture’s Division of Forest Pathology 
at Beltsville, Maryland gives this reassuring note in a recent 
letter to us: “. . . it would seem that there is little likelihood 
that elms will be entirely killed in Europe by the disease. As in 
this country, the disease is sporatic, that is, it is severe in some 
localities but not present at all in others.”’ 
Many reports are available of the efficacy of the control 
measures of local sanitation and spraying (cf, U.S.D.A. Circu- 
lars, op cite, No. 677, pp. 10-12; No. 80, p. 8). Also there are 
reports of the natural recovery of elms once infected by the 
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