PLATE 16 
Agaricus tabularis: 
A.—General appearance of a fairy ring formed by A . tabularis during a dry year. 
The bare zone shows clearly at the right. Scattered through this are a few remnants 
of the short grass and also a few plants of Artemisia frigida. The roots of the latter are 
partly below the soil occupied by the mycelium. Just at the left of this bare area the 
grass is closely cropped and withered. This is the outer stimulated zone of wet 
periods. The illustration does not show the difference between this zone and the 
normal vegetation at the left. Akron, Colo., August 7, 1916. 
B .—General view of a ring formed by A . tabularis; photographed during a dry year. 
The vegetation at the left is normal. Just at the right the withered zone extends to 
the lower right comer of the figure. The vegetation is dry and a little lighter colored 
in this zone. Several old sporophores produced in 1915 are still found in this zone. 
The darker area at the right is the bare zone and within this the inner stimulated 
zone, which, because of the dry period, is not luxuriant. A detailed transect and 
bisect of this ring are shown in figure 13. Akron, Colo., June 11, 1916. 
