PLATE 24 
A. —A trench across the irrigated plot shown in Plate 19, B. Although water had 
been added continuously as rapidly as it was taken up by the soil, there was no 
penetration into the mycelium area, which still remained very dry. The growth of 
the native plants in this area was due entirely to the water available in the upper 
3 or 4 inches of soil. Akron, Colo., June 28, 1916. 
B. —A ring of Calvatia cyathiformis photographed August 21, 1907, 16 miles north 
of Cheyenne Wells, Colo. The ring is not complete; 16 of the 27 fresh puffballs 
should show in this illustration. Fifty-six sterile bases, the remnant of an earlier 
crop, were found in the same zone occupied by the fresh fruiting bodies. Although 
much of this section of country suffered severe drouth in 1907, recent rains had 
caused hundreds of these Calvatia rings to fruit. This ring was fully 200 meters 
