12 liKITISII FUNC.I 



bearing the hj'menium on the under surface, and supported on a 

 central stem, as in Boletus (Plate XXXVII, Figs, i, 3, and 4). 



In the Agaricaceae, the most highly evolved family included in the 

 Basidiomycetes, the idea of securing a large area is obtained by 

 thin ])lates or gills rachating from the stem to the edge of the cap, 

 and placed for protection on the under surface of the cap, as in the 

 common mushroom and all toadstools. Considering tlie amount 

 of material used, the enormous surface area afforded by the gills. 



Polyponts hisptdtis. Tlie fungus has grown very quickly, and has enveloped some 

 pieces of rope lliat were iianging down from a branch above. 



which are completely covered on both sides by the hymenium, 

 this arrangement is far in advance of the arrangement furnished 

 by any previous famil3\ In all the higher forms the cap resembles 

 an open umbrella, supported on a central stem, and the cap literally 

 acts as an umbrella, in protecting the gills from rain and dirt. In 

 many kinds, in addition to the protection afl'orded the gills by the 

 cap, they are also protected by a membrane stretching from the 

 stem to the edge of the cap. 



It must not be imagined that the special characters presented by 



