375 
German Vegetation. 
and in constituent species, and the primary principle of division is 
probably the soundest within an area of fairly uniform climate. 
Dr. Graebner’s complete scheme, really based largely on the 
principle of “ limiting factors,” is one of the most helpful we have 
met with, though it can undoubtedly be criticised adversely in 
various details. 
In the “ special part ” of Dr. Graebner’s book, we have very 
readable and interesting accounts of the different German plant- 
communities. Most of these are essentially like our own, though 
with a considerably richer flora. 
The vegetation of “ sunny hills” described by Graebner (often 
called “ Pontic ” vegetation) has much in common, both in general 
ecological conditions and in actual species, with that of our chalk 
downs. Some of Watson’s “ Germanic ” species, found only or 
mainly in the south-east of England, are characteristic of these 
“ sunny hills.” “ Sandy plains ” with a characteristic vegetation 
are not common in this country, but possibly a parallel may be 
found in parts of our East Anglian heaths. 
Ruderal plants, weeds of arable land and of gardens, show as 
might be expected great similarities and often identity with our own. 
Of Alpine meadows we have none strictly comparable with 
those of Central Europe, and our grassland above the limit of trees 
on the higher Scotch mountains has scarcely been sufficiently 
studied to enable a useful comparison to be made. Of woods, Dr. 
Graebner distinguishes among “ Laubwalder ” (i) Beech, (ii) Oak, 
(iii) Mixed, and (iv) Birch. The German beech-woods are much 
more widely distributed than our own, and have apparently greatly 
decreased in extent, for the reason that they naturally occupy the 
best soils, which have been largely cleared for agriculture. The 
German beech-woods which occupy, according to Graebner, mostly 
marly soils, correspond, no doubt, to those which in England are 
practically confined to the chalk of the south-east. We are probably 
justified in concluding that the English beech-woods also at one 
time covered large tracts of our East Anglian chalk which is at 
present one of the best of our wheat growing areas, and on which 
but few remnants of woodland remain. Over the rest of England 
the Ash is dominant on limy soils, alone on the purer, and mixed 
with the Oak on those with a lower lime-content. Graebner does 
not mention ash-woods of this type as existing in Germany. We 
may therefore conclude that the south-eastern English beech-woods 
on chalk represent the extreme north-western of the continental 
woods, and that beyond the limits of these they are replaced by 
ash-woods. In southern England we have another type of beech- 
wood, locally developed on sands. This type is not mentioned by 
Graebner, though it has a fundamentally different type of ground flora. 
It is not, however, unknown on the continent, since it is described by 
Warming. The general type of ground flora characteristic of Beech- 
woods on limy soil is naturally much the same in Germany as in 
England, since the characteristics of the dominant treeare so strongly 
marked. Many species of course occur in the German woods which 
are absent from the English ones, but the flora is still described as 
“ poor,” and is scarcely likely to be so rich as that of our Ash and 
Ash-Oak types, the richest of our native woodland types. 
Oak-wood is another widely distributed German type, though 
it scarcely seems to occupy so predominant a position as in this 
