Jakob E. Lange: Studies in the Agarics of Denmark. III. 3 



and naked, as the globate cells do not fall apart but from a thin 

 homogeneous cuticle {P. chrysophceus etc.) The fibrillose or cellu- 

 lar texture of the epiderm can be ascertained by means of a 

 good pocket-lens, as the reflection from the globate cells gives to 

 the latter type a micaceous hue. — A transition from one type 

 to the other is formed by those species in which the terminal 

 cells of the fibrils are inflated (clubshaped or almost ovate). Such 

 species (f. inst. P. plaufus) appear to the naked eye as having a 

 somewhat velvety bloom on the surface of the cap. 



The spores are of smaller value for systematic purposes 

 their ontline and size varying but little (from almost spheric to 

 broadly oval). In the subglobose spore the proportion of the long 

 and the short diameter is about 4:3 or 5:4; in the oval 

 about 3:2. 



Rut the cyslidia are very characteristic in this genus. In 

 all the species examined cystidia have been found, and they 

 are generally large and inflated. But while in most cases the 

 edge of the gills is densely set with rather plain-looking, obtuse, 

 inflated-clubshaped or subfusoid cystidia, the sides of the gills 

 are in some cases adorned with ventricose, somewhat bottle- 

 shaped cystidia, crowned with 2 — 5 hook- or thornlike excre- 

 scences. In other species the inflated cystidia have a shorter or 

 longer hairlike appendix. Numerous investigations have con- 

 vinced me that the shape of the cystidia is a constant character 

 and consequently of great systematic value, as it is of a much 

 more precise nature than colour-shades and the like characteri- 

 stics, on which one hitherto chiefly had to rely for singling out 

 the different species. Thus f. inst. P. salicinus and the rather 

 similar P. cinereo-fuscus can at once be distinguished in 

 this way. 



Making use of the microscopic characters for defining the 

 main divisions of the genus a Key can be constructed that will 

 serve as a comparatively easy means to the identification of any 

 species met. 



