336 Chief of a Laboratory of Plant Pathology 



I was able to demonstrate to be similar to the cotton disease, i. e., due to a 

 soil Fusarium. There are large areas in the United States (parts of Carolina, 

 Georgia, Florida, and Texas) where this watermelon disease has prevailed 

 to such an extent that the growing of melons on a commercial scale has 

 been abandoned. . . . The extent of infection in the melon rendered it 

 practically impossible to obtain any resistant plants by the process applied 

 to cotton, namely, by simple selection. Mr. Orton found, however, that a 

 plant known as the " citron " in the United States — that is, a vine with 

 deeply lobed leaves and a hard, striped, roundish fruit, not unlike the 

 watermelon, but inedible until cooked, when it is used for sweet pickles 

 and preserves— was quite resistant to the disease. He used this plant for 

 one of the parents and good varieties of watermelons much subject to the 

 disease for the other, making a number of crosses. The seeds from these 

 crosses when planted gave rise to about a thousand varieties of melons. 

 There were all sorts of fruits — long and short, round and crooked, smooth 

 and rough, plain, deep and pale green, and variously mottled and striped. 

 Of the thousand or more varieties which resulted from these crosses, quite 

 a good many proved resistant to the soil fungus, but only about six 

 varieties had other qualities such as to make them worthy of further con- 

 sideration. The seeds from these six plants were saved and planted the 

 following year on land much subject to the disease in order to test on a 

 large scale the qualities of the melons, and to learn more respecting their 

 resistance to the disease. All continued to be resistant, but only one of the 

 six proved to be a commercially satisfactory melon. The following year, 

 therefore, only this one variety was propagated, but on a large scale and 

 with excellent results. . . . 



Orton' s employment with the United States Department of Agri- 

 culture had begun on June 1, 1899. Arriving early in July at 

 Edisto Island, South Carolina, he soon reported to Galloway that 

 he had been spending his time investigating " the circumstances 

 attending the spread of the cotton wilt, the gathering of informa- 

 tion regarding this and other plant diseases, and the inauguration 

 of some preliminary experiments in checking the disease." This 

 letter was written from James Island, and on August 4 Orton 

 thanked Galloway for " information regarding application of lime 

 and sulphur " and announced from Monetta, South Carolina, " We 

 have a field selected for experimental work with lime and will 

 start the work this fall." He, too, found that the cowpea was 

 susceptible to the disease and he was studying other crops. 

 August 22, however, he informed Galloway: 



I believe that I shall within the next week have done all the field work 

 which can be profitably done here this season, and shall be ready to return 



