146 C. E. Moss, W. M. Rankin and A. G. Tansley. 
I. —Alder-Willow Series: on very wet soils; consisting of 
at least two distinct associations, as yet insufficiently studied to 
allow of satisfactory separation and characterisation. 
II. —Oak and Birch Series: on non-calcareous soils. 
(A) . Oakwood associations : on non-peaty soils at low and 
moderate elevations. 
(a) . Damp Oakwoods : on clays, shales, loams, fine sands 
and moist soils generally. 
[Derived artificial type : Oak-hazel copse]. 
Oak-ash-birchwoods : on shallow well-drained 
soils in a wet climate. 
(b) . Dry oakwoods : on sandstones, grits, sands and dry 
soils generally. 
(B) . Oak-birch-heath association: on dry coarse sandy and 
dry peaty soils (low elevations). 
(C) . Birchwood association: on non-calcareous soils at high 
elevations (from 1,000 feet to the upper wood limit on the Pennines). 
III. —Beech and Ash Series: on calcareous soils. 
(A) . Ash-oakwood association : on calcareous clays, marls, 
impure limestones, and calcareous sandstones: 
[Derived artificial type : (Ash-) Oak-hazel copse.] 
(B) . Ashwood association : on limestones. 
Ash-birchwood : on limestones at high elevations 
(from 1,000 feet to the upper limit of woodland). 
(C) . Beechwood association : on Chalk in the south-east of 
England, with a western extension on the Oolites of the Cotswold 
Hills. 
The characters employed in the classification of English woods 
given in this paper are in the first place the species of dominant 
trees on very wet, on calcareous, and on non-calcareous soils 
respectively. The Oak and Birch series is then sub-divided on the 
basis of the nature and amount of the water-content and on the 
character of the humus. This method is somewhat on the lines of 
that used by Graebner 1 for classifying vegetation, though in the 
absence of sufficiently numerous accurate soil analyses, we have 
relied, for the present, on lime-content, rather than on the general 
content in soluble mineral salts which Graebner employs. The 
1 Naturwissenschaftliche Wochenschrift XIII., 1S98; and Die 
Heide Norddeutschlands, 1901, pp. 24 and 25. Also Die 
Pflanzenwelt Deutschlands, 1909, 
