An Interesting Marasmius Fairy Ring. 



13 



the soil was everywhere covered with fallen needles from the 

 hemlock, and therefore equally subject to the action of the 

 terpenes which they might contain or other organic compounds, 

 arising from the decomposition of the needles. The soil is, how- 

 ever, subject to the action of compounds brought down by the 

 rain-water, which trickles off the trunk of the tree and comes to 

 the ',oi\ close to the foot of the tree. It is well known that hem- 



^^'^-"k. 



Fig. 6. Fairy ring centered around a hemlock tree- 



lock bark contains large amounts of tannin, for which it is val- 

 uable as an article of commerce. It seems quite certain that the 

 rain-water trickling off would bring to the soil greater or less 

 quantities cf this substance, which is known to act deleteriously 

 upon vegetation. Livingston * has shown that the lain-water 

 gathered from oak and chestnut trees had a deleterious influence 

 upon wheat seedhngs and tha author * * ha; previously published 

 an instance of the deleterious action of a Kentucky coffee tree 

 upon ornamental plants growing about its base. 



In the present instance it is evident that the poorest giowth 

 of the fungi is on the lower side of the area, where any excels of 

 water which does not percolate into the soil would flow over its 



♦Bull. 36. Bureau of vSoils. U. S. Dept. of Agr., 1907. 

 * *Plant World, 12:279. 1907. 



