CHAPTER II 



THE VIOLENT DISCHARGE OF THE BASIDIOSPORES 

 (SECONDARY conidia) OF TILLETIA TRITICI 



By A. H. R. Buller and T. C. Vanterpool 1 



Introduction — Bunted Ears and Grains of Wheat — The Germination of the 

 Chlamydospores on Agar — Variations in the Development of the Primary 

 and Secondary Conidia — External Conditions and the Germination of the 

 Chlamydospores — The Development and Discharge of Secondary Conidia — 

 Discussion of the Significance of Violent Spore-discharge in Tilletia tritici — 

 Terminology, New and Old — Nuclei and Sex — Abnormal Basidiospore- 

 discharge — A Basidiospore-discharge Method of making Pure Cultures — 

 Basidiospore -deposits — The Development and Discharge of Basidiospores in 

 Dry Air — The Germination of Basidiospores — The Development of Chlamydo- 

 spores in Culture Media — Spore-fall observed by the Beam-of-light Method — 

 The Distance of Basidiospore-discharge — The Spore-fall Method of Inoculating 

 Wheat Seedlings — The Infection of Wheat Seedlings by Secondary Basidio- 

 spores of Tilletia tritici and T. laevis — The Swelling of Bunted Wheat Grains 

 in Water — The Reactions of the Promycelium to External Stimuli — The 

 Phenomenon of Protoplasmic Migration — Conclusion 



Introduction. — The Stinking Smut disease or Bunt of wheat 

 (Fig. 100), which occasions enormous losses in our wheat crops, has 

 always been a serious factor in wheat production. Doubtless, it 

 surprised prehistoric man when he first brought wheat under 

 cultivation, and it is referred to in the writings of the ancient Greeks 

 and Romans. The earlier speculations as to the etiology of Bunt 

 were of a superstitious nature ; but, as the centuries went by, the 

 opinion gained ground that the disease is produced within the 

 plant itself by a fermentation of the sap brought about by adverse 



1 My co-operation with Professor Buller in carrying out the investigations 

 recorded in this Chapter was made possible by my election to the Hudson's Bay 

 Company Fellowship at the University of Manitoba for the year 1925-1926. — 

 T. C. Vanterpool. 



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