38 THE CURLY-TOP OF BEETS. 



10. Cobb, N. A. Letters on the diseases of plants, 2d series. Miscellaneous 



publication Xo. 6(56, Dept. of Agriculture, Sydney, New South Wales, 1904, 

 pp. 38-50. 



Cobb here describes stigmonoses of apple, pear, and other fruits. 



11. Cunningham, Clara A. A bacterial disease of the sugar beet. Botanical 



Gazette, vol. 28, 1899. 



A disease of beets in which a leaf -curl is conspicuous is described, and 

 the writer concludes that it is caused by bacteria in the root. This is 

 not clearly established. 



12. Czapek. Berichte der Deutchen Botanischen Gesellschaft, vol. 15, 1897, pp. 



516-520. 



Czapek demonstrated a relation of oxidizing enzyms to geotropic curva- 

 ture in root of several genera of plants, which suggests the possibility 

 that there may be such a relation between oxidizing and reducing sub- 

 stances in plants sensitive to certain parasites. 



13. Golden, Katherine E. A disease of the sugar beet root. Proceedings, 



Indiana Academy of Science, 1891, p. 92. 



This paper describes the isolation of bacteria from roots of beets 

 affected by a leaf-curl. 



14. Huston, H. A. Sugar beets. Bulletin 39, part 2, Purdue University Agri- 



cultural Experiment Station, 1892, p. 49. 



The abnormal appearance of certain beets prepared for analysis is 

 described. 



15. Koning, C. Zeitschrift fur Pflanzenkrankheiten, vol. IX, 2, pp. 65-80. 



Koning largely confirms the work of Beijerinck and others on mosaic 

 diseases. 



16. Kramer, Ernst. Die Bacteriosis der Runkelrube (Beta vulgaris L.), eine 



neue Krankheit derselben. Oesterreisches Landwirtschaftliches Central- 

 blatt, vol. 1, 1891, pt. 2, pp. 30-36, and pt. 3, pp. 40-41. 



Kramer refers to a disease bearing some resemblance to curly-top as 

 " bacteriosis." 



IT. Lapham, M. H., and Heileman, W. H. Field operations of the Bureau of 

 Soils, II. S. Dept. of Agriculture; soil survey of the Lower Salinas Val- 

 ley, California, 1901, p. 506. 



The writers found an acid reaction in the soil of fields where curly-top 

 was noted, while the disease did not occur in this district where the soil is 

 alkaline to litmus. 



18. Loew, Oscar. Letter to A. F. Woods, dated December 12, 1902, as follows : 

 " The observation that you made, that oxidase can kill diastase, has been 

 made by my assistant (Suzuki) in the case of mulberry leaves. Dis- 

 eased leaves have more oxidase than healthy ones and no longer trans- 

 port starch." See Bulletin of the College of Agriculture, Tokyo Imperial 

 University, vol. 4. no. 4. 



19. Physiological studies of Connecticut leaf tobacco. Report 65, U. S. 



Dept. of Agriculture, pp. 11-25. 



20. Mayer, Adolph. Die Landwirtschaftlichen Versuchs-Stationen, vol. 32, 

 1886. 



Mayer was the first to make a careful study of the mosaic disease. He 

 found that it can not be caused by an insufficient supply of mineral con- 

 stituents in the soil. 

 181 



