Floripa and California Laboratories 229 



Tumors on the roots of peach trees have been found by the writer in 

 several localities during the past few years, and have been reported from 

 many parts of the United States. They occur on roots of all a^cs, and 

 vary greatly in size, the larqest ones bcin^ several inches in diameter. 

 Usually these tumors are several to many times the diameter of the root, 

 and are entirely unlike the small galls produced by nematodes. They also 

 occur on stems above ground, peach trees thus affected having been 

 received from Texas and Tlorida. 



This disease occurs from New Jersey to Florida and westward to the 

 Pacific, but at present it is most prevalent in Texas and California, where 

 it is causing much anxiety. In California it attacks orchard trees as well 

 as nursery stock, and seriously injures both. . . . 



It has been obsefved by the writer on the peach, plum, almond, pear, 

 and poplar, and it has been reported as occurring on the roots of other 

 trees and shrubs, e. g., apricot, apple, fig, walnut, raspberry, blackberry, 

 and vine, and root tumors of some sort certainly occur on these plants. 



The inner tissues in young specimens of the peach and almond tumors 

 appear to be entirely free from nematodes and fungi, bacteria, and phy- 

 tomyxineae, and their cause is involved in uncertainty. The most probable 

 hypothesis is that they are due to some external irritant. Those who have 

 the opportunity to examine early stages of this disease should certainly look 

 for external parasites, especially animal organisms. . . . 



Since December 1892, crown gall as a fleshly outgrowth on 

 roots of deciduous fruit trees had been described in the literature 

 of the state experiment stations. That year C. M. Woodworth, 

 in a bulletin of the California station, had called attention to the 

 disease. Edward J. Wickson, Professor of Horticulture of the 

 university at Berkeley, had written on it. Liberty Hyde Bailey, 

 in his Annals of Horticulture for North America during the year 

 1892,^ had referred to it in an article on " Plant Diseases and 

 Insects," and, with every year the literature grew until such leading 

 authorities as Atkinson and Bailey in New York, Halsted in New 

 Jersey, Taft in Michigan, Augustus Dawson Selby, botanist of the 

 Ohio Agricultural Experiment Station, and others, had dealt with 

 it.^ During the year 1893 Smith corresponded on the subject with 

 John Scott, horticultural commissioner of the county of Los 

 Angeles, California, and received several lots of specimens of 

 the disease, representing different phases. March 3, 1894, Toumey 

 wrote again to Smith: 



* New York, 1893, Rural Publishing Co., pp. 94-124. See also the Annals for 



1891, p. 109. 



° Published accounts relating to crown-gall, op. cit., 9. 



