414 CORN-SMUT. LEAF-SMUT OF TIMOTHY. 



tive medicinal and poisonous properties, and it has been demon- 

 strated that abortion and certain diseases of the feet of cattle fol- 

 low the prolonged use of ergotized hay or pasturage. How many 

 of the smuts and other fungi of grasses possess similar or other 

 detrimental properties is at present merely a matter of conjec- 

 ture ; but some of them occur in sufficient quantity to merit sus- 

 picion until they have been shown to be harmless. 



SMUTS. 



1. Corn-smut (Ustilago zece mays, D. C.). Order Basidiomy- 

 cetes. Sub-order Ustilagineae. Forming galls, often of large 

 size, in the leaves and other parts of Indian corn and teosinte, 

 that are finally transformed into dusty masses of brown spores. 



No fungus is more widely distributed or better known than 

 corn-smut. Like other smuts, its germinating spores attack 

 young plants, its mycelium or spawn making its way upward 

 through their growing tissues without producing any evident ef- 

 fect until it prepares to fruit, when it increases and leads to the 

 formation of the smut-galls, that are ultimately filled with 

 myriads of round brown spores, each densely covered by short, 

 sharp spines. These spores, which measure 9-13 micro-millime- 

 ters, preserve their power of germination for several years, or, in 

 fresh barnyard manure, etc., they develop at once, multiplying 

 indefinitely by the production of yeast-like secondary spores, 

 each of which has the power of infecting a seedling corn plant. 



Gathering and burning the smut-galls and smutty ears, while 

 they are still green, to prevent the accumulation of spores in the 

 soil , rotating the crop when smut has become firmly established 

 in a field; treating seed corn with copperas-water and lime, etc., 

 before planting ; and using only old, well-rotted manure or arti- 

 ficial fertilizers, have all been proposed as preventives of smut. 



2. The leaf-smut of Timothy (Tilletia striaeformis, Westd.) 

 Forming black, smutty lines in the leaves of Timothy and other 



