GENERAL SUMMARY 



THE FOLLOWING IS A SUMMARY OF THE MORE IMPORTANT 

 RESULTS OBTAINED DURING THE INVESTIGATIONS 



Chapter I. Typically, the hymenium of Hymenomycetes consists of 

 basidia, paraphyses, and cystidia. Two nuclei fuse together in each 

 young basidium, and every basidium eventually produces spores. There 

 is no nuclear fusion in paraphyses and cystidia, and these elements are 

 sterile from the first. 



In all Hymenomycetes, the spore has a little projection or hilum at 

 its base, which projects toward the axis of the basidium. From this 

 hilum, a few seconds before spore-discharge, a tiny fluid drop is excreted. 

 The drop grows to a maximum size which is usually equal to about 

 one-half the diameter of the spore. Then the spore is shot violently away 

 from its sterigma. The drop clings to the spore and is always carried 

 away by it. Sometimes the drop is not excreted at all and sometimes 

 the excretion is excessive. Under these conditions the spores are never 

 discharged from their sterigmata. 



The author discusses, but is not able to explain satisfactorily, the 

 mechanism of spore-discharge. The fluid drop excreted by the hilum 

 of the spore is not improbably an indication of some chemical or physical 

 change taking place in the cell- wall. 



A basidium never produces more than one generation of spores upon 

 its sterigmata. Direct observations made upon living disterigmatic and 

 tetrasterigmatic basidia (Psalliota, Calocera, Panaeolus, etc.) show that 

 a basidium, 15-30 minutes after discharging the last spore it bears, 

 collapses and dies. 



There is a relation between the volume of a basidium and the total 

 volume of the spores which it bears. In Psalliota campestris (cultivated 

 form) the volume of a spore of a monosterigmatic basidium is twice that 

 of one of the spores of a disterigmatic basidium. 



In the Hymenomycetes, the sterigma, in association with the hilum 

 of the spore, is to be regarded as an organ specialised for bringing about 

 violent spore-discharge. In the Gastromycetes, in which the spores are 

 not violently discharged, the sterigmata are either suppressed or imper- 

 fectly developed, and the spore-hilum is altogether lacking. Typically, 

 in the Hymenomycetes, each basidium bears four spores separated from 



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