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~ 
30 CIRCULAR NO. 120, BUREAU OF PLANT INDUSTRY. 
being punctured or torn. Leaf-cut injuries, on the other hand, rep- 
resent an actual destruction of some of the tissues of the leaf, leay- 
ing irregular holes or marginal incisions. In single words, leaf-curl 
may be described as distortion of the leaves, leaf-cut as mutilation. 
In allusion to this distinction the word * tomosis” is proposed as a 
technical name for the leaf-cut disorder, while the distortion caused 
Fic. 1.—Young plant of Egyptian cotton grown at Lanham, Md. The lower leaves are 
affected by leaf-cut and upper leaves hy leaf-curl. (Natural size.) 
by the plant lice may be called “ hybosis.” The insects inhabiting — 
the badly distorted upper leaves of figure 1 were identified by Mr. 
Th. Pergande, of the Bureau of Entomology, as Aphis gossypu 
Glover. aa 
And in addition to the open wounds that result from leaf-cut there 
are usually some that have healed, giving a characteristic torn-and- 
mended appearance. Such scars, like other leaf-cut wounds, often 
[Cir. 120] 
