VEGETABLES. 475 



TREMELLA NOSTOC. 



Though the weather may have been ever so dry and burn- 

 ing, yet after two or three wet days, this jelly-like substance 

 abounds on the walks. WHITE. 



FAIRY RINGS. 



The cause, occasion^ call it what you will, of fairy-rings, 



subsists in the turf, and is conveyable with it : for the turf of 

 my garden-walks, brought from the down above, abounds 

 with those appearances, which vary their shape, and shift 

 situation continually, discovering themselves now in circles, 

 now in segments, and sometimes in irregular patches and 

 spots. Wherever they obtain, puff-balls abound ; the seeds 

 of which were doubtless brought in the turf. WHITE *. 



* [So long ago as the year 1675 a paper on the subject of Fairy Rings 

 appeared in the ' Philosophical Transactions,' by Mr. Jessop, in which he 

 propounded the theory of the electrical origin of these curious phenomena ; 

 and in 1807 a paper was read at the Royal Society by Dr. Wollaston, on 

 the chemical causes which were believed to produce them. At the 

 meeting of the British Association in 184G a communication by Professor 

 Way took a similar view. The electrical theory was advocated by Mr. 

 Dovaston in an article in the ' Magazine of Natural History,' vol. xiv. 

 More recent investigations by Professor Buckman are recorded in the 

 1 Veterinarian ' for 1870 ; and an elaborate paper on the chemical theory, by 

 Dr. Gilbert, will be found in the ' Journal of the Linnean Society,' Botany, 

 vol. xv. p. 17. These, however, do not, as it appears to me, solve the diffi- 

 culty of the h'gure and growth of the rings. Whatever may be the origin 

 of the fungi which are always the associates of these phenomena, there 

 can be no doubt of the fact that, as a general rule, the plan approximates 

 more or less to a circle or the segment of a circle, that it is at the cir- 

 cumference that the fungi always appear, and that by some " centrifugal 

 law," as Professor Balfour expresses it, the circle gradually extends and 

 that if a portion of turf infested by one of these be introduced into a lawn 

 or other piece of grass, the interloper continues to increase and to spread 

 in spite of every attempt to extirpate it. It appears to me that a tendency 

 to a centrifugal development, so remarkable in many of the tribes of fungi, 

 especially in certain species of Agaricus, Bohtus, Lycopcrdon, &c., is neces- 

 sary to account for the figure and extension of fairy-rings, independent of 

 chemical or electrical intervention, by which many of the phenomena 

 connected with them may be modified or produced. T. B.] 



