298 



RESEARCHES ON FUNGI 



area and also the significance of the existence of the various areas 

 to which the phenomenon of mottling is due. 



In regard to the question of successive generations, it is first 

 to be remarked that on any one area, owing to the fact that the 

 basidia come to maturity in succession, a great many more spores 

 are safely ripened and discharged than would be the case if the 

 basidia were all to develop simultaneously. The space above any 



mm 



FIG. 102. Panaeolus campanulatus. A, surface view of a piece of exhausted 

 hymenium. The basidia had produced about 159 spores as shown by the 

 number of sterigmatic stumps ; a, exhausted basidia ; e, paraphyses ; s, 

 a waste spore. B, the 159 spores of A set in the upright position close 

 together ; the area is about 1/5 times as large as A. C, a surface view of a 

 piece of hymenium of the same size as A, seen in the middle of the spore - 

 discharge period. The spores on A were distributed at any one time during 

 the spore -discharge period as at C ; a, past-generation basidia ; 6, present- 

 generation basidia ; c, coming-generation basidia ; d, future-generation 

 basidia ; e, paraphyses. Magnification, 387. 



given area for the protrusion of the basidia and the extension of 

 their spreading sterigmata and spores is limited. If all the basidia 

 on the area endeavoured to occupy it simultaneously, there would 

 be nothing but confusion : the basidia would so jostle each other 

 and interfere with each other's development that the spores would 

 become matted together and their chance of successful ripening 

 and discharge would be reduced almost to nothing. This can 

 best be realised by reference to an actual area, one that was drawn 

 with the camera lucida and is represented in Fig. 102, A. This 

 area, as one may reckon by counting the number of sterigmatic 

 stumps, produced 159 spores. Each spore in its upright position 

 occupies a certain horizontal area. If all the 159 spores were to 



