PSALLIOTA CAMPESTRIS 



409 



number of spores on individual basidia was determined by the 

 method just described, i.e. by the examination of the living 

 hymenium in surface section. It was found that this number is 

 not identical for Wild and Cultivated Mushrooms. 



In Wild Mushrooms gathered in several places in England 

 (Birmingham, Redditch, etc.) the number of spores on each basidium 





.:. 





.. 





 



. 

 * Vn 



* 







O 



*.*. 



FIG. 143. Psalliota campestris. Camera-lucida drawings of the spores of the 

 present-generation basidia on the living hymenium. A and B, from a wild 

 form of the fungus ; C, from a cultivated form. In A, the basidia are tetra- 

 sporous with one exception which is trisporous. In B, in addition to the 

 tetrasporous basidia, there are a number of trisporous basidia. The spores of 

 the tetrasporous basidia are shown black, whilst those of the trisporous are 

 shaded with lines. In C, most of the basidia are bisporous, but others are 

 monosporous. The spores of the bisporous basidia are shown black, whilst 

 those of the monosporous are shaded with lines. Magnification, 440. 



was usually four ; but here and there on the hymenium, mixed 

 with these quadrisporous basidia, were frequently found a certain 

 number of trisporous basidia which occurred either singly or in 

 little groups. In Fig. 143, A, is shown a small area of the hymenium 

 in which only one trisporous basidium is associated with the normal 

 quadrisporous basidia, while at B is shown another similar area 

 in which trisporous basidia are almost as numerous as the quadri- 

 sporous. In these drawings, all the groups of four spores have 

 been represented in uniform black, whilst the groups of three spores, 

 for the sake of distinction, have been shaded with straight lines ; 



