Oct. 29, 1917 
Fungus Fairy Rings 
229 
of Agaricus tabularis , while on the adjacent land it soon penetrates and 
disappears. Several hours after a rain the surface soil will be muddy just 
above the dry hypha-filled portion. When these hyphae are dry, water 
is turned off just as from a dense mass of nonabsorbent cotton. The 
figures in Table XXI do not fully convey the difference in moisture 
penetration since under field conditions the moisture is free to run off on 
adjacent land and the relative amount of water which penetrates the soils 
of the Agaricus tabularis fairy ring is consequently smaller than would be 
indicated by the table. The effect of rain in moistening the soil of an 
Agaricus tabularis ring is shown in Plate 15. The mycelium-filled soil 
shows light in the soil trench. The water penetrated both in front of and 
back under the edge of the mycelium-filled soil without wetting the 
latter. The moist soil appears dark in the soil trench. 
Table XXI. —Rate of penetration (in cubic centimeters per hour) of water into the soil of 
an Agaricus tabularis ring, Akron, Colo., IQ15 
Record No. 
Outside. 
At the 
border of 
withered 
and bare 
areas. 
In the bare 
or nearly 
bare area. 
First record, begun June 12. 
' 12 - 5 
3 °. 8 
41.7 
83-4 
< 4 i. 7 
41.7 
83-4 
83-4 
83.4 
20. 9 
12. 3 
6.4 
41.7 
20. 9 
6.4 
7.6 
27. 8 
10. 8 
22. 7 
20. 9 
9-3 
22. 7 
22. 7 
83*4 
60. 0 
22. 7 
22. 7 
Average. 
55-7 
17. 2 
31*9 
ftprwnH rppnrrl Qturip nlare. hefnin Tune 26 . 
' 87.0 
46. 5 
87. 0 
105.0 
< 74.0 
87.0 
105. 0 
95-3 
105. 0 
69. 0 
44 - 5 
44 - 5 
69. 0 
87. 0 
27.4 
29. 0 
69. 0 
46. 5 
46. s 
69. 0 
69. 0 
46- 5 
46. 5 
69. O 
105. 0 
27.4 
29.9 
i Cvvl vl 7 PCV 11 iv uittvv j MVft iJ 11 j uuvi »v * ■ * * • » * 1 * 1 * ' * 
Averaere. 
88.0 
54 *o 
56.5 
EFFECT OF FAIRY RINGS ON VEGETATION 
RINGS OF AGARICUS TABULARIS 
The first effect noted by the penetration of the filaments of this fungus 
into the soil occupied by short-grass vegetation is the slight stimulation 
of all the native plants. The stimulation (fig. 3, zone 4) is noted in the 
deeper color of the short grasses and in the greater and more rapid growth 
of the annuals (Plantago purshii, Festuca octoflora, Hedeoma nana, etc.) 
