Heath Association on H nut head Common. 161 
To summarise the preceding remarks we would distinguish 
the following four successive stages in the recolonisation of burnt 
ground on the heath at Hindhead. (a) Sprouting ot the gorse. 
(b) Appearance of new growth from the base of other members of 
the heath-flora and development of a number of seedlings (gorse 
dominant), (c) Calluna , Erica cinerea, Ulex minor and to some 
extent Pteridium and Vaccinium competing for dominance (CUE 
facies), (d) Calluna (tall) and Ulex minor dominant, all other forms 
subsidiary (C U facies). Judging by the number of annual rings it 
would appear that the gorse-plants in the low and high Calluna- 
zones are almost invariably a year older than the corresponding 
Calluna- plants—an observation which indicates that also in these 
regions of the heath the gorse has been the first coloniser. 
A word may be added on the behaviour of Ulex minor during 
the recolonisation of burnt ground. The shoots that arise from the 
old plants are at first all procumbent (PI. V, fig. 4), but already during 
the first season following a fire upright branches appear on some of 
the plants. These upright branches however appear to grow but 
slowly in the first years, and it is only when Calluna , Erica and other 
forms are growing up all round that some of these upright shoots 
of the gorse begin to grow more vigorously and develop into the 
upright branches, described on p. 152. It is probably only those 
upright shoots that do not project far beyond the level of the 
surrounding heath that manage to survive the drying influence of 
the winds and that remain as upright shoots in the C U facies. 
It is a familiar fact that after a heath-fire bracken often tends 
to appear in far larger quantity (cf. footnote on p. 158). As regards 
the area burnt in 1911, which bore very little Pteridium before the 
fire, there is some slight evidence of increase, but no very decisive 
proof can be adduced at present. The area burnt in 1909 lay 
largely within the zone in which bracken is a dominant, but here 
again we have hitherto failed to obtain any really decisive evidence 
of a marked increase. It may be pointed out that owing to the 
rapidity with which Ulex minor recolonises the ground, the bracken 
may not obtain those facilities for spreading its domain, which it 
finds on heaths not so largely occupied by gorse. We hope to be 
able to give further data on this point in later communications. 
On the south-eastern slopes of the central ridge leading down 
to the valley B a number of land-slides have occurred some years 
back, whereby considerable stretches of yellow gravel of a rather 
coarse character have been exposed. This gravel extends to a depth 
