Oct. 29,1917 
Fungus Fairy Rings 
205 
the observation that, where two circles met, both were obliterated at the 
point of contact, and said: 
The exhaustion occasioned by each obstructs the progress of the other, and both 
are starved. 
Fig. 8.—Remapped area shown in figure 2. During the fall of 1915 a portion of the area mapped in figure 2. 
was plowed and planted to fall wheat. During June, 1916, the area was remapped. This area is 400 by 
290 meters and comprised the portion lying next to the experiment station grounds. A compari¬ 
son with figure 2 will show that none of the Calvatia rings could be detected in the wheat crop the follow¬ 
ing year. Of 12 Agaricus rings mapped in 1915, 9 were easily detected in the wheat field in 1916. 
Way (1847, p. 43) thought that— 
The theory of de Candolle, that these rings increase by the excretions of these fungi, 
being favorable for the growth of grass but injurious to their own subsequent develop¬ 
ment on the same spot, was insufficient to explain the phenomena. 
