Floristik, Geographie, Systematik etc. 633 



accompanvinii- the earlier Vegetation maps amounted to a few pages, 

 a substaniial volume is now required to contain the material gathered 

 in the course ot" the survey. The memoir on the Peak District 

 is however more than a botanical description of 430 Square miles 

 ot" England, since it includes a summary of much of the earlier 

 work, and the author also states at greater length certain views 

 alread}^ put forth b}^ him, notably on the concept of a plant-forma- 

 tion, and the reasons underlying the contrast bctwecn the Vegeta- 

 tion of calcareous and non calcareous soils. The district offers good 

 opportunities for such studies since it includes lowland and also 

 the southern end of the Pennines with altitudinal zonation up to 

 630 raetres, with considerable climatic Variation from lower to 

 higher altitudes. The rocks and soils have also a wide ränge inclu- 

 ding calcareous, siliceous and acidic peaty soils; glacial deposits 

 are also absent from most of the area. Some of the land is under 

 cultivation, mainly as grassland, but a large area is uncultivated 

 grassland, heath, moorland, and woodland. 



The memoir includes two coloured Vegetation maps, printed 

 on the Ordnance Survey maps with a scale of one inch to one mile 

 (l : 63360). Pure or combined colours and numbers or letters are 

 assigned to each type of Vegetation, and the scale allows of a con- 

 siderable ränge, briefly indicated bere by the colour scheme, which 

 also Shows the Classification of plant communities: 



1) Plant formation of acidic peat: a) moor with Vaccinmm 

 Myrtülus dominant, b) moor with Eriophorum vaginatian, c) moor 

 with Cnlluna vulgaris, d) moor with mixed Eriophorum and CaUiina, 

 e) moor with mixed Vaccinium and Calluna, f) retrogressive Erio- 

 phorum moor. 



2) Plant formation of siliceous soil: a) wood with Quercus sessi- 

 liflora dominant, h) wood with Betula piibescens, c) siliceous grass- 

 land with Nardiis stricta and Pteris aquilina, d) siliceous scrub, 

 e) siliceous grassland with much Calluna. 



3) Plant formation of sand}' soil: wood with Quercus Robur 

 dominant. 



4) Plant formation of calcareous soil: a) wood with Fraxiniis 

 excelsior dominant, b) calcareous grassland with Festiica oviita, 

 c) calcareous scrub, d) calcareous grassland with much Calluna. 



5) Plant formation of cultivated land: a) zone with Avena (Oat), 

 b) zone with Triticum fWheat), c) transitional zone, d) plantations 

 of deciduous trees chieflj'- Fagus sylvatica, e) plantations of conife- 

 rous trees chiefly Pinus sylvestris and Larix deddua^ f) mixed woods. 



The text of the memoir can only be indicated briefl\' here. An 

 introduction (p. 1—37) outlines the general features of the district. 

 The area overlying the Goal Measure series of rocks has low hills 

 with gentle slopes, while the Millstone Grit and adjacent strata 

 forms the central massif with moorland plateaux, steep escarp- 

 ments and deep Valleys; all these sandstones and shales have the 

 Valley slopes characterised b}^ woods of Quercus sessiliflora, but 

 these is much cultivation and grassland. The features of the southern 

 part are largely determined b.y the Mountain Limestone with 

 plateaux. escarpments and steep Valleys, with grassland, scrub, and 

 woods of Fraxinus excelsior. Two text-maps show the distribution of 

 the rocks and soils. and a comparative table gives the plants cha- 

 racteristic of calcareous, siliceous, and acidic peaty soils respecti- 

 vely. Features of the climate are also summarised. 



The woodland associations (p. 38—87) are grouped as shown 



