260 



Mycologia 



in woods. Although extremely variable, it is recognized with- 

 out much difficulty by the character of its spiny covering, the 

 larger spines somewhat resembling the shape of cut gems. The 

 plants generally grow near together and are occasionally cespi- 

 tose, but are rarely so crowded as in the case of the pear-shaped 

 puffball. 



Agaricus campestris L. 



Common Mushroom 



Plate 15. Figure 4. X 4 



See Mycologia for March, 1909, for a full description and 

 colored illustrations of this species. Fatal mistakes are some- 

 times made by extremely ignorant and careless persons who 

 are unable to distinguish the common mushroom from the white 

 form of the deadly amanita. The differences between the two 

 are very marked, even if the base of the stem with the volva has 

 been left in the ground. The common mushroom may at once be 

 known by its pink gills, which become almost black with age, 

 while those of the deadly amanita are always white. 



Dictyophora duplicata (Bosc) Ed. Fisch. 

 Veiled Stinkhorn 



Plate 15. Figure 6. X 2 



The " egg " of this poisonous and very fetid stinkhorn may be 

 found beneath the soil or slightly projecting above the ground, 

 about buildings and near old stumps in fields or borders of 

 woods. It is nearly white, with a pinkish tinge, rather heavy, 

 firm when very young, but becoming softer to the touch as it 

 matures. When cut through in a very young stage, as shown in 

 the figure, the young white cap and stem may be seen within, 

 surrounded by a zone of gelatinous matter, which has a pinkish 

 coloration. In later stages, the lines of division are more 

 marked. This "egg" is considered very poisonous and must be 

 carefully distinguished from puffballs when collecting the latter 

 for food. The mature stinkhorn, after the development from 



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