June, 1913.] The Mosaic Disease of the Tomato. 
169 
problem from an etiological standpoint. Curly-Top of sugar 
beets has been an exceedingly baffling disease. Not until (190S) 
did investigators grasp the situation and the cause was not dis¬ 
covered until (1910). In this year Shaw proved it to be due to an 
active agent introduced by the bite of the beet leaf hopper. In 
(1912) Bunzel devised his apparatus for measuring the oxidase 
content of plant juices quantitatively, and applied it in determin¬ 
ing the oxidase content of curly-top of beets in 1913, showing that 
the leaves of curly-top plants have an oxidase content two or 
three times that of healthy leaves. During the past year the 
writer has made a study of an apparently similar disease of the 
Raspberry, known as Raspberry Yellows or Curl, which although 
never previously reported, has occurred quite abundantly in Ohio 
for the last seven years. In addition to these, Peach Yellows, 
Little Peach, Peach Rosette and other plant diseases have often 
been regarded as enzymic diseases, but the writer knows of no 
detailed investigations of the enzymes supposedly concerned. 
BIBLIOGRAPHY. 
Allard, H. A., 1912. The Mosaic Disease of Tobacco. Science n. s. 
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Appel, O. und Schlumberger, O., 1911. Die Blattrollkrankheit und 
unsere Kartoffelernten. Arbeiten der Deutschen Landwirtschafts. 
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Bayliss, W. M. and Starling, E. H., 1902. The Mechanism of Pancreatic 
Secretion. Journal of Physiology. 28:325-353. (Not seen). 
-, 1911. The Nature of Enzymic Action. 2nd. Ed. London. 
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-, 1899. Weitere Beitrage zur Kenntniss der Tabakspflanze. Land- 
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235. (Same as German article cited below). 
-, 1898. Ueber ein Contagium vivium fluidum als Ursache der 
Fleckenkrankheit der Tabaksblatter. Verh. der Koninkl. Akad. van 
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(1899. Rev. Centralbl. f. Bakt. 25:27-33.). 
--, 1899. Bemerkung zu dem Aufsatz von Herrn Iwanowski uber 
die Mosaikkrankheit der Tabakspflanze. Centralbl. f. Bakt. 2 25:310- 
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-, 1899. De'lexistence d’un principe contagieux vivant fluide agent 
de la Nielle des feuilles de tabac. Archiv. Neerland. des Sc. Extractes 
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