CAUSE AND NATURE OF CROWN-GALL 9 



the past eight years and in the following States, viz : California, 

 Arizona, Texas, New Jersey, New York, Michigan, Alabama, 

 and Ohio. Woodworth, 5 Wickson, 6 and W. K. Smith 7 have 

 published regarding it in California; Tourney 8 in Arizona; 

 Yates" and Price lu in Texas ; Halsted " in New Jersey ; Atkin- 

 son u and Bailey" in New York; Taft u in Michigan, and 

 Selby 15 in Ohio. Dr. Erwin F. Smith " ; has also called atten- 

 tion to this disease in various publications. Atkinson, Selby, 

 and Bailey consider the disease the same as the Wnrzelkropf 

 which occurs in Germany and other European countries. 

 Sorauer 1T discusses the foreign disease at some length and con- 

 cludes that it is not caused by the action of a parasite, but by 

 some disturbing influence occasioned by the short cutting or 

 bending of the roots of the plant when transplanted or by the 

 abnormal development of adventitious buds, possibly induced 

 by an unusual flow of sap. 



Sorauer's description certainly corresponds in many particu- 

 lars with the disease as it is in Arizona, and the figures which 

 accompany his description fairly well illustrate the crown-gall 

 as known in America. The following quotations, translated 

 from Sorauer's work, are descriptive of crown-gall : 



"The swellings appear generally at the crown of the roots 

 of young trees, the enlargements having the size of hazelnuts 

 or walnuts. In older specimens they may attain the size of 



5 Bull. Cal. Agr'l Exp. Sta., 99 (1892) ; Ann. Repts. iSga-'gzi, 436, and 



i894-'95. 2 3'- 

 6 Bull. Cal. Agr'l Exp. Sta., 99 (1S92). 



7 Cal. Fruit Grower (December 15, 1894, 481). 



8 Bull. Ariz. Agr'l Exp. Sta., 12 (1894) ; Ann. Rept. 1899, 235 ; Timely 

 Hints for Farmers, 5 (1899). 



9 Cal. Fruit Grower 1895, in. 

 10 Bull. Texas Agr'l Exp. Sta., 39, 841 (1896). 



"Repts. Hot. N. J. Agr'l Exp. Sta. 1895, 359; 1896, 413; 1898, 354; 

 Bull. Torr. Bot. Club, XXIV, 509. 



12 National Nurseryman (August, 1893). 



•'Bulls Cornell Agr'l Exp. Sta., 74, 383 \ "7, 3 6 7- 



14 Rept. Mich. Agr'l Exp. Sta. 1897,96. 



15 Bulls. Ohio Agr'l Exp. Sta., 79, ioS, 127, 1 39 ; 92, 208, and 104, 211 ; 

 Rept Ohio State Hort. Soc, 29, 75. 



16 Jour. Myc, VII, 376; Bull. Torr. Bot. Club, XX, 363. 



17 Handbuch der Pflauzenkrankheiten, I, 737 (1896). 



