95 



SMUT IN WHEAT. 



By F, Abbott, Superintendent of the Botanical 



Gardens. 



At tlie last meeting of the Royal Society a communication 

 from Mr. Joseph Barwick was read on Smut in Wheat, in 

 which he relates his own tests for the purpose of ascertaining 

 iihe cause, and suggests that further experiments should be 

 carried out in the Botanical Gardens for a like purpose. 

 Having carefully read Mr. Barwick's communication, I can 

 but think that he, as well as others with whom I have 

 conversed, are not acquainted with much that has been done 

 of late in the investigation of this subject, and that, 

 therefore, the following general notes may interest many : — • 

 The various species of Ustilaginse, especially U. Segetum, 

 causing smut in wheat and other plants have been under 

 observation by a host of comj^etent scientific observers for 

 many years past, and it is only of late, after much patient 

 research and many thousands of anatomical observations, 

 m.ore in the laboratory than the field, that the life history of 

 the fungus has been elucidated. In the Gardener's Chronicle 

 for February 23 and March 2, a detailed account of recent 

 discoveries as to the nature of Ustilaginse is given by H. 

 Marshall Ward. As this account is replete with information 

 at present little known, arrangements have been made for its 

 publication in Webster's Gazette for August and September, 

 where full details may be found. To others into whose hands 

 this publication may not come, the following brief notes may 

 be of interest : The dark substance, popularly called smut, is 

 in reality dense masses of spores arising in tufts at the ends 

 of fine filaments, formed in the ovary or young grain at the 

 expense of the food material, which is destroyed. These 

 spores, of which there are enormous numbers, every ear of 

 smutted corn producing, it is estimated, not less than ten 

 millions, are capable of germinating when placed under 

 favourable circumstances, and multiply their conoidal cells 

 with great rapidity in the soil ; fresh manure or manure 

 washings greatly favour their development, and should in all 

 cases be avoided ; in material of this description the fungus 

 produces generation after generation in vastly increasing 

 numbers, waiting as it were for the coming of its host, into 

 which it quickly penetrates, and with which it continues to 

 grow. The spores ripening in the grain of the smutted 

 cereal are garnered with the latter, become scattered on the 

 healthy grain and are sown with it, the fungus germinating 

 at the same time as the cereal, produce their prymocella, the 

 germ tubes of which penetrate the embryo plant. Experiments 



