8 
DEVELOPMENT 
diately beneath unfit for its production. The spawn, how¬ 
ever, spreads all round, and in the second year produces a 
crop, whose spawn spreads again, the soil behind forbidding 
its return in that direction. Thus the circle is continually 
increased, and extends indefinitely till some cause intervenes 
to destroy it. If the spawn does not spread on all sides at 
first, an arc of a circle only is produced. The manure 
arising from the dead fungi of the former years makes the 
grass peculiarly vigorous around, so as to render the circle 
visible even when there is no external appearance of the 
fungus, and the contrast is often the stronger from that 
behind being killed by the old spawn. This mode of 
growth is far more common than is supposed, and may 
be observed constantly in our woods, where the spawn 
can spread only in the soil or amongst the leaves and 
decaying fragments which cover it.” Later writers hold 
that a single fungus does not usually give rise to the circle 
in pastures, but that anything which may kill a small patch 
of grass— e.g., heaps of rotten manure—and thus provide a 
suitable matrix, may be a cause. The rings sometimes 
assume enormous dimensions. A heavy dressing of manure 
tends to break them up. Worthington Smith makes the 
following interesting observation : “ I have known a ‘ fairy¬ 
ring ’ of Clitocybe geotropa on Dunstable Downs for forty or 
more years, which, under favourable conditions of light, can 
be seen at a distance of more than a mile. The diameter 
has not altered much during the time I have known it, for 
sometimes it grows inwardly for several years, and then 
again outwardly.” 
The mycelium gives rise to the perfect fungus. In the 
orders with which the present volume deals—the Basidio- 
mycetes and Ascomycetes—it is styled spovophove and asco- 
phove respectively. 
In the Basidiomycetes the spores are borne on a club- 
shaped body, the basidium ; in the Ascomycetes they are 
