FAIRY RINGS are spots or circles in pastures, which are either more bare than the rest of the field, or more green and luxuriant. Frequently a bare ring appears, like a footpath, with green grass in the center, and the circle which the ring forms, or of which it might form a part, is often some yards in diameter. These rings began to attract the attention of men of science in the latter part of the last century, and various hypotheses were suggested to account for them. Some imagined that they might be the effect of lightning. Dr. Withering appears to have been the first to ascribe them to the growth of fungi. Dr. Wollaston further investigated the subject, which has more recently been very fully investigated by prof. Way; and it is now perfectly ascertained and univers ally admitted, that F. H. result from the centrifugal development of certain kinds of fungi, especially of Agaricus oreades, A. yambosus, A. coccineus, and A. personatus. The
common mushroom (A. campestris) shows a tendency to grow in the same manner. Prob ably the spot where the agaric has already grown is unfitted for its continued nourish ment, and the mycelium (spawn) extends outwards to new soil, the fungus unfitting the soil to which it extends for the immediate nourishment of grass, but enriching it after wards by its own decay. The mycelium of many fungi has certainly a tendency to extend outwards from a center; and decayed fungi, containing not a little of the phos phate of potash, are a highly stimulant manure for grasses. F. H. of large size some times occupy the same situation for many years. The circle is almost always imperfect, some accidental circumstance having arrested the growth of the mycelium on one side.