74 
Growth is, therefore, slow, and in, the case of the species 
typical of the heath, the lings and heathers, stunted. The growth 
form is almost exclusively xerophytic, as is shown by the small 
size of the leaves, their in-rolling, the stunted growth of the stems,, 
the creat length of the roots, and the occurrence in them of 
mycorhizal fungi. 
On the drier and fresher soils of sand or gravel in pits that 
have recently been dug for road metal, the Scotch heath, Erica 
cinerea is fairly well mixed with the dominant ling, and when in. 
bloom in early summer is a beautiful feature of the heath. In 
damp places near springs or heath streams the cross-leaved heath, 
Erica Tetralix is mixed with the ling. In similar stations, on the 
heaths in the neighbourhood of Corfe and Wareham, the pretty 
Dorset heath, Erica ciliaris } occurs. Another, but more widely 
distributed, associate of much beauty is the marsh gentian,, 
Gentiana pneumonanthe. Small tufts of the moor-gass, Molinia 
ccentlea , hide much of the peaty surface layer beneath the ling 
and with it occur the creeping stems, with short erect spring 
branches, of the dwarf gorse, Ulex nanus. The abundance of this 
gorse, though generally quite unobtrusive, is one of the distinctive 
features of the South Hampshire heaths. The growth of th eCladonia 
lichens encrust old dry peat beneath the ling. These, together 
with the mosses, Polytrichum. sp. and Dicranum. sp. also play an 
important role in the preparation of bare soil for the occupation 
of higher plants. The common gorse, Ulex europoeus , occurs on 
the heaths, but rarely away from the sides of the roads or foot 
tracks, its distribution being closely related in some way to human 
occupation. 
Some rare associates of the local calluna heaths recall the- 
heather moors of higher latitudes. These are the crowberry, 
Empetrum nigrum , which has been recorded for the heaths about 
Poole Harbour, but not within the borders of Hampshire, Listera 
cordata, Lycopodium Selago, and Lycopodium clavatum. It is 
just possible that these are relics of the heaths of an earlier cooler 
period. 
1 he origin of the heath is a subject of great interest, but it 
can only be just touched upon at the present occasion. 
I he heath may originate in a variety of ways. 
I he loose sand of sand-dunes on the edge of the sea after a 
period of exposure to the atmosphere'may, as at Studland Bay, 
pas5 over from the dominance of the marram grass into that of 
the ling. 
Flats of shingle that have been long accumulated and drenched 
bv rain slowlv become inhabited bv mats of ling. 
I he coarse sandy soil of the Bagshot Sands is naturally sa 
devoid of plant nutriment as to be incapable of supporting any 
vegetation except such, as makes the minimum of demand upon 
it. It is, therefore, highly probable that from its first uncovering 
it has been occupied by vegetation of the heath type. With other 
sands and gravels which contained on their first exposure a fair 
