252 RESEARCHES ON FUNGI 



unequal size and of the most diverse shapes. In their totality, 

 therefore, they do not give rise to any regular pattern. It is 

 also to be remarked that the mottling on one side of a gill does 

 not correspond with that on the other: the opposing hymenial 

 areas develop quite independently of one another. One rule, 

 however, appears to hold, namely, that the sum of the darker 



FIQ. 88. Panaeolus campanulatus. Part of one of the gills drawn with 

 a camera lucida to show the mottling of the hymenium. In the 

 darker areas the basidia bear black spores which are nearly or 

 quite mature. In the lighter areas the basidia bear spores which 

 are either colourless or are only beginning to turn brown. Magni- 

 fication, about 10. 



areas always exceeds by a considerable margin the sum of the 

 lighter areas (cf. Fig. 88). For this rule a good explanation will 

 be forthcoming when we have studied the development of one 

 small portion of the hymenium. 



Mottling of the gills is one of the most obvious field-characters 



of the Panaeoli. Indeed, the generic name Panaeolus, which we 



owe to Fries, 1 was chosen on this account : it is derived from 



the Greek word panaiolos meaning all-variegated or mottled. The 



1 E. Fries, Epicrisis, Upsaliae, 1836-38, p. 234. 



