96 



phenomenon. The observation requires no skill except what is necessary to find 

 the male organs of reproduction at the right time, and crush them under the 

 coverglass and recognize the manubrium. If nothing else comes of it it can not 

 fail to add one, and that one the most striking and one of the most easily attain- 

 able of all, to the stock illustrations of the circulation of protoplasm. 



Fungicides for the Prevention of Corn Smut. By Wm. Stuart. 



During the present century the disease of the corn popularly known as "corn 

 smut" ( Usiilago zen-mayp, [DC] Wint.) has engaged the attention of some of its 

 most eminent botanists. It has only been within the last half of the present 

 century that the life history of the fungus has been well understood. When we 

 consider that corn is the jjrincipal cereal crop of America, it is not to be won- 

 dered at that any fungus disease causing it much apparent injury should arouse a 

 desire on the part of investigators to devise some means of preventing it. 



The successful treatment of the smuts of wheat and oats by disinfection of the 

 seed, either by hot water or chemical solutions, naturally turned the attention of 

 Experiment Station workers to employing the same remedies for the smut of corn. 

 The experiments of Arthur, ^ of Indiana, Kellerman and Swingle,^ of Kansas, 

 and those of Pammel and Stewart,^ of Iowa, are perhaps the most noteworthy. 

 These experiments included the disinfection of the seed by hot water and chem- 

 ical solutions; the attempted infection of the seed by rolling in the spores of tlie 

 smut; and the spraying of the plants with fungicides, the latter experiment being 

 conducted by the Kansas Experiment Station* in 1890. The results of all these 

 experiments were of a negative character, due to the fact that the fungus plant of 

 the corn smut, unlike that of wheat and oats, can enter any young growing tissue 

 of the host, while in the last two mentioned it can onlv enter the host when it is 

 very young. This point has been ably demonstrated by Brefeld, ' who, by a long 

 series of carefully conducted experiments, showed conclusively that the germinat- 

 ing spores, or conidia, are capable of penetrating any portion of the young 



'Fourth Annual Report Indiana Experiment Station. 



'Kansas Experiment Station Bulletins, Nos. 22, 23, 40, 41. 



'lovya Experiment Station Bulletins Xos. 16, 20, Proceedings of Iowa Academy of 

 Sciences, 1894, p. 74. 



^Kansas Bulletin No. 23, p. 101. 



"Journal of Mycology, Vol. VI, Xos. I, II, and IV. (Translated from Nachrichten aus 

 dem KIul) der Landwirthe zu Berlin, Nos. 220, 222, by Erwin Smith.) 



