18 THE NATURAL HISTORY OF BRITISH GRASSES. 
to point out some of those affections of a fungoid form to 
which grasses seem more particularly liable: those which 
more commonly attack cereals have been explained before 
the Society by Mr. Sydney in his usual felicitous manner, 
under the names of Red Robin, Mildew, Smut, and Bunt, 
with others of this class, all of which are more or less com- 
mon to the grass tribe in general, though perhaps not to so 
great an extent in the wild grasses as in the cereals. 
The smut (Uredo segetwn) is constantly found attacking 
the grass-flowers, but oftener, perhaps, on the flowers of 
Arrhenatherum avenaceum than on any other species. I 
have seen whole patches of this grass covered with the 
black efflorescence of the fungus; here, however, as the 
object is not grain, it produces but little mischief, though 
the attacked grass is always stunted in its growth. 
The greatest mischief done by fungi to grasses is that 
occasioned by the agaric, or mushroom tribe; and more 
especially by those which form the circles in meadows, 
known as fairy rings. These often make a turf look very 
dissightly ; and though it has been said that they manure 
the grass, as evidenced from the circle of greener grass 
where they have decayed, yet we must remember that this 
ring of green is always surrounded by another of brown 
withered herbage, consisting of nearly dead grasses; and, 
indeed, it is in the decay of these that the phosphatic salts 
which Professor Way has shown to exist so abundantly in 
this tribe of fungi are supplied. 
It may be here stated, that the fungus upon which the 
Professor experimented, and upon which his paper was 
founded, is the Agaricus prunulus, a plant which is abundant 
in all poor upland pastures in Gloucestershire, and conse- 
quently the fairy-rings which are formed by them are at all 
seasons of the year a good criterion of the value of a field. 
This fungus is remarkable for growing in the month of 
May, on which account it can be distinguished from its 
congeners, as other fairy-ring agarics do not appear until 
the autumn, and then frequently in the same rings as those 
