364 RESEARCHES ON FUNGI 



and that, in all probability, it had produced a series of successive 

 annual crops of fruit-bodies above the dark-green zone. Bayliss 

 observed that in one of the rings of Marasmius oreades, the well- 

 known Fairy Ring Fungus, where the radius of the ring was already 

 nearly four and a half feet, the radial increase of size of the ring 

 through the growth of the mycelium was in four successive years 



FIG. 130. Two fairy rings of Psalliota (= Agaricus) tabularis, containing large 

 fruit -bodies about 15 cm. in diameter and of relatively uniform size. Photo- 

 graphed at Akron, California, U.S.A., June 7, 1909, by H. L. Shantz and 

 R. L. Piemeisel. Courtesy of the United States Department of Agriculture. 



6, 9-5, 10-5, and 13-5 inches respectively. 1 In other instances 

 she found very similar results which showed that the tendency of 

 each ring was to extend more and more rapidly as it gets older 

 and as its radius increases. Probably the rings of Psalliota cam- 

 pestris behave very similarly. The ring which I found to have a 

 diameter of 3 yards may well have been enlarging for six or 

 seven years with accelerated speed. Owing to the rarity of fairy 



1 Jessie S. Bayliss, " Observations on Mamsmhis oreades and Clitocybe gigantea 

 as Parasitic Fungi," Jmirnnl of Economic Biolog;/. 1011, vol. vi. p. 118. 



