CHAPTER XI 



STROPHARIA SEMIGLOBATA 



General Remarks Description of the Hymenium in Detail -Rate of Discharge 

 of the Spores of a Basidium and Collapse of the Basidium-body The Spore- 

 fall Period Wasted Spores 



General Remarks. In this and the two following Chapters, we 

 shall endeavour to extend our knowledge of the Panaeolus Sub- 

 type by studies made upon Stropharia semiglobata, Anellaria 

 separata, and Psalliota campestris, the Common Mushroom. 



Stropharia semiglobata is one of the commonest of field fungi. 

 Like Panaeolus campanulatus, it is coprophilous and grows on horse 

 dung in pastures throughout Europe and North America. Whilst 

 wandering over grazing grounds at Sutton Park in Warwickshire, 

 England, in the autumn, I have often seen hundreds of fruit-bodies 

 on a single day. The fungus also occurs at Winnipeg and has come 

 up spontaneously on horse dung which has been brought into the 

 laboratory. There can be but little doubt that the spores of this 

 species, like those of the Coprini and coprophilous fungi in general, 

 are able to pass uninjured through the alimentary canal of horses 

 and cattle. A proof of this statement, so far as horses are con- 

 cerned, seems to be afforded by the following consideration. The 

 winter at Winnipeg is so severe and prolonged that, for a period of 

 about five months, no fungus can develop its fruit-bodies out-of- 

 doors. In mid-winter, when horses drop their faeces on the snow 

 in the open, the dung-balls immediately become frozen. Now, at 

 this season, infection by air-borne spores of Stropharia is impossible 

 since, owing to winter conditions, no such spores are being liberated. 

 Yet, on several occasions, dung-balls, after having been collected 

 in January or February in the frozen condition and set in covered 

 crystallising dishes in the laboratory, have given rise in the course 



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