50 THE SCOTTISH BOTANICAL REVIEW 
The following six chapters are mainly taken up with descriptions 
of the plant formations of clays and loams, of sandy soils, of the 
older siliceous soils, and of calcareous soils, where the chief plant 
associations are believed to have been woodlands. These have been 
largely destroyed by the hands of man, but interesting descriptions 
of the former vegetation have been reconstructed from the patches 
of existing woodland, pastures, and so-called waste ground. The 
authors hold the view that the chief associations of the plant forma- 
tions of each of these soil types is a type of woodland having dis- 
tinctive characters, and that each type of woodland passes into 
retrogressive associations of scrub and grassland. ‘Thus the plant 
formation of clays and loams has a chief association of ‘damp 
oak-wood,” with Quercus pedunculata dominant, and retrogressive 
associations of scrub and “neutral” grassland. That of the sandy 
soils has a chief association of ‘‘ dry oak-wood,” with Quercus pedun- 
culata and Q. sessiflora co-dominant, and retrogressive associations 
of scrub and grass-heath. That of the older siliceous soils, framed 
to include the soils of the metamorphic and palzeozoic non-calcareous 
rocks, has a chief association of woods, with Quercus sessiflora 
dominant, and retrogressive associations of scrub and “siliceous” 
grassland. The plant formation of calcareous soils is subdivided 
into two subformations of the older limestones and of the chalk. 
The former has a chief association of ash-woods, with subordinate 
associations of scrub and “limestone” grassland ; while the chalk is 
shown as having associations of beech-woods, ash-woods, yew, scrub, 
and chalk grassland. The description of the chalk is probably the 
most interesting, from the naturalist’s point of view, that has yet 
been published. 
The heath formation, which seems to the writer to have greater 
claims as a natural unit of vegetation than any of the above, is 
described by itself in Chapter 1V. It is pictured as having several 
woodland, heath, and grass associations, and a diagram is given to 
show the probable genetic relations of the plant communities of the 
formation of sandy soils and of the heath formation. 
In Chapter X. we find an interesting account of the river valleys 
of East Norfolk, including the physiographical relations of the streams 
and broads, with their aquatic and fen formations. The conditions 
affecting the aquatic associations, such as the alkalinity, circulation, 
aeration, and depth of water, and the factors of light and shelter, are 
shortly discussed. The various forms of fen and fen-car are con- 
sidered in detail, and their relations shown by sketch-maps and 
transects. The great moor formation is described in Chapters XI. 
and XII. There is an excellent account of the development of the 
lowland moors of North Lancashire from fens which formerly 
occupied the position of estuaries and lakes, Marsh and fen are 
followed by woodland, and this in turn by moorland associations. 
This description is accompanied by vertical sections of the peat, 
showing the succession of the vegetation. 
The upland moors of the Pennines and the grass moors of the 
