OF BRITISH FUNGI. 67 



exact limit of the ring towards the centre. Very com- 

 monly there is to be observed an outer and contiguous 

 ring, much narrower than the inner, and of which the 

 grass is either short and weak, or faded and brown, 

 remarkably contrasting with the vivid green of the 

 inner ring : on this brown ring, or just upon its margin, 

 fungi are found. The duration of fairy-rings varies 

 much ; some disappear in a few weeks, others endure 

 for years. A severe winter will obliterate the external 

 traces of a ring, and prevent the usual crop of fungi 

 appearing upon it at the proper season ; but such rings 

 often reappear, and are thus considered to have been 

 suddenly formed. During the whole course of their 

 appearance the rings increase in diameter, spreading 

 outwards from the centre, the faded brown circle becom- 

 ing rank with green and copious grass, and a fresh outer 

 circle being formed of dead or feeble blades of grass. 

 The rate of increase is various, some enlarging their 

 diameter a few inches in the year, others as many feet. 

 The circles frequently meet in the course of this 

 gradual enlargement. In such cases the point of con- 

 tact becomes obliterated ; and when this contact occurs 

 between the margin of several such rings, the oblitera- 

 tion of the parts which meet leaves a variety of 

 segments of circles upon the turf, which, pursuing an 

 independent course, and some increasing more rapidly 

 than others, present eventually an unaccountable irre- 

 gularity, and, as it were, patchwork of greener and 

 paler, stronger and weaker, portions of turf. When 

 the turf is cut through such a ring at two contiguous 

 p 2 



