460 YEARBOOK OF THE DEPARTMENT OF AGRICULTURE. 



(6) Tlie pileus of the deadly agaric is tliinner than that of the com- 

 mon mushroom, and, froig. being rather bell-shai^ed wlien young, 

 becomes gTadually flat-topped Trith the center a little raised. In 

 breadth it is intermediate between the two preceding species. The 

 stalk usually is longer than the breadth of the pileus, and the habit is 

 slenderer than in the two preceding species. All three species are 

 pleasant to the taste, which shows that one can not infer that a species 

 is not poisonous because the taste is agreeable. The fly agaric has 

 scarcely any odor. The other two species have certain odors of their 

 o^Ti, but they can not be described. 



VARIETIES OF THE COMMON MUSHROOM AND CLOSELY RELATED 



EDIBLE SPECIES. 



Having learned in detail the distinctions between the common 

 mushroom and the two poisonous species most frequently mistaken 

 for it, some of the varieties of the common mushroom and a few edi- 

 ble species closely related to it will now be considered. The pileus of 

 the mushroom has been described as smooth and without scales. 

 Varieties are not infrequently found in which the surface is more or 

 less flocculent and with flat, tufted scales. The scales, however, are 

 not prominent, and are not at all like the large, angular warts on 

 the fly agaric, which can be easily scraped off the otherwise smooth 

 surface, whereas the scales of common mushrooms are formed b}' the 

 breaking up of the siu^f ace into a sort of fringe, which can not . be 

 pulled off without tearing the pileus. There is also an excellent 

 variety of the mushroom, which may perhaps better be called a 

 closely related species, which has an agreeable flavor of almonds. 

 It should not be understood, however, that this is the only fungus 

 whicli has a flavor of almonds, but it is the only one with this flavor 

 that is closely related to the common mushroom. 



THE HORSE MUSHROOM. 



The horse mushroom (Agaricus arvensis) looks very much like the 

 common mushroom, but is considerably larger, being sometimes 8 or 

 10 inches broad, or even broader. It frequently passes for the ordi- 

 nary mushroom, and, in fact, most of the large specimens sold as the 

 ordinary mushroom are in reality Agaricus arvensis. It grows fre- 

 quently in hedges and in cultivated places, and differs from the 

 mushroom in having the pileus generally a more shining white, in 

 having the stem a little hollow as it matures, in the fact that the gills 

 are at first white and do not change to a brownish purple until com- 

 paratively late, and especially in having a ring which is comi^osed of 

 two adherent layers, the inner being a smooth membrane and the 

 outer shorter and cut up in a steUate manner. On PI. XXIV, repre- 

 senting the liorse mushroom, tlie peculiarity of the ring is shown. 



