OBSERVATIONS ON VEGETABLES. 425. 
and the skirts of coppices. Some truffles, he informed us, lie two 
feet within the earth, and some quite on the surface ; the latter, he 
added, have little or no smell, and are not so easily discovered by 
the dogs as those that lie deeper. Half-a-crown a pound was the 
price which he asked for this commodity. Truffles never abound 
in wet winters and springs. They are in season, in different 
situations, at least nine months in the year.— WHITE. 
TREMELLA NOSTOC. 
Though the weather may have been ever so dry and burning 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 appear- 
ances, 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. 
* Several causes have been assigned for the presence of fairy rings, as they are termed, 
an appearance occurring in pasture lands cf a dark ring, as if the grass was of more 
luxuriant and of a darker green. We have sometimes observed the ring incomplete. 
Wherever we have noticed these, fungi have been present, which afterwards would spring 
up in the line of the circle, and to their presence we believe the appearance is now 
generally attributed. The regularity of the dark mark calls attention, but the tracks of 
the fungi, or the lines in which they will spring, may frequently be observed to run quite 
irregularly, showing also a dark green mark. 
