PLATE 22 
Agaricus tabularis: 
A. —A ring formed by A . tabularis in a field of Turkey wheat. The bare zone is 
the only prominent zone in this ring. The dry season prevented the development 
of luxuriant growth on the stimulated zones. Akron, Colo., June io, 1916. 
B. —A trench across the ring shown in the figure above. The soil under the bare 
zone was permeated with the mycelium and was very dry. Akron, Colo., July 18, 
1916. 
