92 Journal of Agricultural Research voi. xm, no. a 



Habitat: On partly decayed tubers and roots of plants, such as 

 Solatium tuberosum, in Europe and America (collected by Wollenweber) 

 and Ipomoea batatas in the United States of America (collected by 

 Harter and Field (21, p. 257). 



On partly decayed tubers and roots of plants. Cause of potato dry- 

 rot and jelly-end rot. Identified from the following: Ipomoea batatas 

 (collected by Mr. L. L. Harter) ; Musa sapientum (collected by Mr. S. F, 

 Ashby, Jamaica, Porto Rico) ; soil (collected by Mr. F. C. Werkenthin, 

 Austin, Tex.) (2, p. 206)., 



On rotted tubers of Solatium tuberosum, in Oregon, Idaho, and Cali- 

 fornia (14, p. 258). 



Werkenthin {ly) in 191 6 reported it from the soils of Texas. It was 

 reported in a previous paper by the writer (//) as occurring on the roots 

 of Populus deltoides at Jerome, Idaho, and was demonstrated to be the 

 cause of a blackrot of the Irish potato tuber in Idaho. While on a tour 

 of southern Arizona in November, 191 5, F. radicicola was isolated 

 several times from decaying roots of Egyptian cotton (Gossypium bar- 

 badense) and alfalfa (Medicago sativa) plants growng on irrigated lands 

 in the Salt River Valley, near Phoenix, Ariz. The fungus was there 

 found associated with a form of the rootrot of cotton and alfalfa, and 

 the conditions under which it was found suggested that it must have 

 entered the plant roots from the soil. It was isolated nine times from 

 Idaho soils as follows: Once each from sample i and groups A and C, 

 twice from sample 2, and four times from sample 3. 



MACROSPORIUM 



Macrosporium commune Rabenh. 



Identified once from sample i and once from sample 2. This species 

 was also once identified from decaying roots of an opuntia growing in the 

 desert near Jerome, Idaho. 



MONASCUS 



A single species of the genus Monascus was once isolated from group A. 

 It is briefly described as follows: Mycelium, white to gray; perithecia 

 abundant, globose, black, seated on compact mass of mycelium, 15 to 18 ;x 

 in diameter; asci, one, filling the perithecium, many-spored; spores, oval 

 to elUptical, hyalin, minute, 3 to 5 by i to 2 /x. Fungus in mass on 

 steamed melilotus stem, dark -gray to black. 



MUCOR 



Six species of the genus Mucor were identified, and nine other uniden- 

 tified forms were isolated. These nine forms apparently differed from 

 each other and from all other species described, but it is not certain that 



