Floristik, Geographie, Systematik etc. 115 



map. The maritime zone includcs plant associations of Zostera ma- 

 rina, salt marsh , and a rock belt. From the seashore the ground 

 rises steeply so that there is little low-lying ground, mainly derelict 

 grassland. A woodland belt is developed up to 200 metres on the 

 open coast with higher extensions up the streams. The most exten- 

 sive woods are Oak and Birch, but alder occurs with Hazel in 

 moister areas. Pteris occurs with the woodland and extends some 

 distance higher, where the soil is deep enough and neither too wet 

 nor boggy; in this area it avoids the steep northern sides of hüls 

 with little direct sunshine. An extension of the Pteris zone in recent 

 years is traced to the replacement of mixed grazing with cattle, by 

 sheepgrazing alone. Calluna occurs mainly above the Pteris zone, 

 and is followed on the higher heights by "grasslands" giving place 

 on the higher summits to Rkacomitrium lanuginosum , Vaccinium 

 Myrtillus, V. Vitis-idaea, and Empetrum nigrum. This zonation is 

 not quite so regulär as might be inferred, owing to local variations 

 of the area. The paper furnishes a useful glimpse into the Vegetation 

 of western Scotland, an area not studied yet in detail. 



W. G. Smith. 



Searth, G. W., The Grassland of Orkney. (Trans. Proc. Bot. 

 Soc. Edinburgh. XXIV. 3. p. 143-163. 1911.) 



A contribution to the ecological Classification of grassland, taken 

 from a larger survey now in preparation on the land Vegetation of 

 the Orkney Islands. Grassland is defined by the dominance of 

 grasses or plants generally associated with grasses, on soils ranging 

 from those dry in summer to those permanently wet, which are 

 generally loamy with or without raw humus but with no distinct 

 formation of peat. Grassland is frequently produced from other na- 

 tural lormations by the action of man operating in various ways. 

 In classifying types of grassland, the author regards as fundamental 

 the recognition of two types, one (wet pasture formation) with a 

 wet soil due to ground water, the other (dry pasture formation) 

 with the moisture of its substratum derived mostly from direct 

 precipitation. Another factor is acidity since grassland occurs on 

 substrata ranging from acid humus to alkaline calcareous soils. 

 Assuming these concepts, the author groups the types of grassland 

 in his area into formations and sub-formations, and gives the ecolo- 

 gical characters of the more important associations with selected 

 examples, but for details reference to the original paper is necessary. 



W. G. Smith. 



Tansley, A. G., Types of British Vegetation. (Cambridge, 

 Univ. Press. 416 pp., XX, 36 pl. 21 figs. 1911.) 



The aim of this book is to bring together the results of investi- 

 gations on types of Briüsh Vegetation , and to classify them as far 

 as possible in a scientific manner. So far as actual publications 

 extend, the plant-communities of Br itain might appear to be incom- 

 pletely examined, but the book is much more than a summary. 

 Some chapters are contributions appearing here for the first time, 

 and a large amount of field-work has been undertaken specially to 

 secure at least a primary survey. The evolution of the book is indi- 

 cated in the preface: it is a direct outcome of the work of the 

 Committee for the Survey and Study of British Vegetation, it is 

 the Joint work of a number of authors, and a consistent treatment 



