HEMIBASIDIOMYCETES 38 1 



throughout the affected areas. They are light in color, often nearly 

 hyaline. The distribution of the spores is only effected by disinte- 

 gration of the leaf. There are, however, conidia in the life history 

 of some species of this genus of smuts. In this species they are 

 scolecosporic in form, 30-55 x 1-2 p. No very serious diseases 

 of cultivated plants are induced by species of Entyloma, although 

 the genus is rich in forms. 



Entyloma compositarum Farl. is widespread in the United States 

 upon a variety of the composites, including among these species 

 of Ambrosia, Aster, Erigeron, etc. The minute sori occur in the 

 leaves. The spores are subspherical or ovoidal, 9-14/4, and hyaline. 

 The under surfaces of the leaves may be profusely covered with 

 the conidial form, which is in this case like a species of Cercospo- 

 rella with relatively short spores and conidiophores. The conidia 

 are fusiform or slightly clavate and measure 1 5-20 x 2-3 p. 



Entyloma Ranunculi (Bon.) Schrot. 1 is found upon various 

 species of Ranunculaceae. The life history of this form has been 

 carefully studied. 



X. ONION SMUT 

 Urocystis Cepulce. Frost 



SELBY, A. D. Onion Smut. Ohio Agl. Exp. Sta. Built. 122: 71-84. figs. 



3,4. 1900. 

 SIRRINE, F. A., and STEWART, F. C. Experiments on the Sulphur-Lime 



Treatment for Onion Smut. N. Y. Agl. Exp. Sta. Built. 182: 145-172. 



1900. 

 STURGIS, W. C. Transplanting, as a Preventive of Smut upon Onions. Conn. 



Agl. Exp. Sta. Kept. 19 : 176-182. 1895. 

 THAXTER, ROLAND. The " Smut " of Onions (Urocystis Cepulce). Conn. Agl. 



Exp. Sta. Kept. (1889): 129-153. pis. 1-2. 



Habitat relations. The onion smut has been known as an 

 important disease-producing organism in the United States for 

 about forty years, the first published notes of its effects being 

 in the reports of the Massachusetts State Board of Agriculture, 

 1869 to 1870. The fungus seems to be of American origin and 

 its injuries are very largely confined to the eastern states, particu- 

 larly New England. It occurs, however, as far west as Indiana. 

 It would not appear that climatic conditions affect the prevalence 



1 Ward, H. M. On the Structure and Life History of Entyloma Ranunculi 

 -(Bon.). Phil. Trans. Royal Soc. London. 178 B: 173-185. pis. 3, 4. 1887. 



