252 Floristik, Geographie, Systematik etc. 



rogams and more than 3600 Cryptogams. Two new species: Aristo- 

 leca trilocularis Sind. Sarcochiliis yninutißos a.re descrihed. The coloured 

 plates are useful and the large number of figures, many of which 

 are of dissections, illustrate all groups of plants including fungi 

 and algae. A. D. Cotton. 



Bews, J. W., An ecological Survey of the Midlands of 

 Natal, with special reference to the Pie ter maritzburg 

 District. (Reprint, Ann Natal Museum II Pt. 4. 485—545. 1 map. 

 7 pl. 1914.) 



The author has already published a general account of the 

 Vegetation of Natal (Bot. Cent. 120. p. 52), The present contribution 

 is a more detailed survey of an area of 450 Square miles. A map 

 is provided (scale about 1 : 100,000) which shows the chief plant 

 formations, geological substrata, and topographic features; it is the 

 first detailed map of this area. 



Regional factors are throughout recognised as important in 

 determining the distribution of Vegetation, these include topographic, 

 edaphic, climatic and the influence of man. 



The primary division of the plant formations is into High \'eld 

 and Low Veld. Natal rises by a series of terraces intersected by 

 the main river Valleys, hence each terrace has parts at a higher 

 level — High Veld — , and parts at low levels — Low Veld. The 

 high veld receives the greatest precipitation, the temperature is 

 more equable, and although the soils are deep and well-aerated 

 they are poor in nutritive salts. The low veld is much drier, with 

 great extremes of temperature, the soil is a compact clay badly 

 aerated but rieh chemically. All ecological factors tend to impoverish 

 the high veld and to enrich the low veld. Anthistaria imberbis is 

 dominant over much of the veld, a tall form on high veld, and a 

 rarely flowering form on the low veld. Associations of several spe- 

 cies of Andropogon and other grasses occur as subdominants under 

 special conditions. 



The Bush formation is associated with the high veld on south- 

 eastern slopes with much moisture and shelter from hot winds. 

 This is a formation intermediate between sclerophyllous woodland 

 and tropical rain-forest. It has been much destroyed by human 

 influence and by fire, so that in many parts vestiges only remain, 

 and these are gradually replaced by Andropogon and other grass 

 associations. The Thorn Veld formation occurs within the low veld 

 Zone; Acacia spp. and other trees have umbrella-form, more or less 

 thorn development, and thick bark so that they are adapted to 

 withstand Invasion by grass-fires. 



The Rocky Hillside formation presents manj^ facies on the 

 slopes of both high and low veld. 



The Vlei or marsh formation is also distributed without respect 

 to altitude, and like the last is regarded as a coUection of unstable 

 plant formations in contrast to the more stable types of veld, bush 

 and thorn. There is a considerable ränge of associations according 

 to degree of wetness and stagnancy. Streams and riv^er-banks für- 

 nish another series of unstable plant formations. 



Each of the seven formations is described in considerable detail 

 with exhaustive lists of characteristic plants. The effects of human 

 interference on each is also discussed, and incidentally the memoir 

 contains much information on the agriculture of Natal, and the 



