Stinking Smut ^or Bunt in Wheat. 



79 



peculiar structure were not to be mistaken, a circumstance whicli I have never 

 before observed, nor am I aware that the fact has been noticed by others." 



The occurrence of bunted and clean ears in the same stool has already- 

 been fully referred to in Chapter VIII., and bunted and clean grains in the 

 same ear are illustrated in Plate II., B and C. 



That the grain of wheat itself in a diseased ear should be only partially 

 bunted, is regarded by some as an impossibility, nevertheless, two examples 

 have been met with this season, confined to a single ear in each case, and one 

 of them is here photographically illustrated. This belonged to the variety 

 known as Cedar, grown at Dookie Agricultural College, and the one ear con- 

 tained all the gradations of sound, bunted, and partially bunted grains. The 

 three partially bunted grains were partly translucent and partly opaque and 

 dingy, indicating, apparently, the diseased and healthy portions. On making 

 transverse and longitudinal sections of the diseased grains, fungus filaments 

 and numerous spores were found interspersed between the outer skin and 

 aleuron layer on one side, while the other portion was of the normal character 

 and filled with starch granules. (Fig. 10.) In a longitudinal section, the 

 embryo was seen to be quite intact and partially surrounded by the numerous 

 spores, some of which were still in the early stage with fungus filaments at- 

 tached. The species belonged to Tillitia tritici, with the spores of which the 

 plants had been originally infected. The other specimen was found on Genoa, 

 grown at Burnley, and the ear contained sound and entirely bunted grains, 

 and only one partially bunted. This variety was infected with T. levis. so 

 that both species of smut produced partially bunted grains. 



I have had a partially bunted grain photographed, both as it naturally 

 appeared, and in section, because Bolley-^ has stated very distinctly and em- 

 phatically, after making hundreds of sections of apparently sound grains, 

 that " In a crop of stinking smut, the grain product is made up of solid grains 

 and smut balls only. In other words, there are no grains which are partially 

 smut and partially flour." I grant that such an occurrence is exceedingly 

 rare, but it shows how diffcult it is to prove a negative. 



Fig. 9. — Grain of wlioat partially buutoJ. Surface view 



prain p;irtially 



