NOTES AND ABSTRACTS. 



647 



July 12 either all the ground was covered or only 10 per cent, free 

 of vegetation. 



Introduced weeds obtain a footing only in the already closely- 

 grown meadow, not in the open dry grassland. — G. F. S. E. 



Vegetation of Natal. By J. W. Bews {Jour. Ecol. vol. ii. 

 No. 3, pp. 206-7 ; 8 plates). — This is a summary of a longer 

 account pubhshed by the author in the Annals of the Natal Museum, 

 the plates from which are here reproduced. In considering the factors 

 influencing the plant-communities of the area dealt with, the Pieter- 

 maritzburg district, the author lays stress on the influence of 

 topography and physiography, while the recent important concepts 

 of stable and unstable habitats and of growth-forms are emphasized 

 in his classification of these communities. The vegetation of the area 

 is divided into seven natural plant-formations and an eighth consisting 

 of plantations, mainly of wattle [Acacia). The first and much the 

 most extensive is the veld formation, dominated by grasses and 

 divided into high and low veld, the latter having a deeper but less 

 well-aerated soil than the former. The bush formation occurs in the 

 high veld region, the bush itself consisting of a forest of two layers 

 of trees, mostly evergreen, with abundant lianas, some epiphytes, but 

 rather scanty undergrowth ; where the bush is cleared the area becomes 

 occupied by veld grasses, and on the margin of the bush formation 

 there is a zone of transition to veld, where, according to the conditions 

 as to protection or the occurrence of fires, &c., one formation passes 

 into the other. The thorn veld formation occurs in the low veld 

 region, and would be more extensive but for the periodic fires. The 

 rocky hillside formation consists of scrub, which is developed in the 

 high veld region and is intermediate between bush and thorn veld ; 

 it is characterized by aloes, spurges, &c. The alpine plant formation 

 occurs on the fiat mountain-tops and consists of species not found 

 at lower altitudes, though on the mountain- sides the veld formation 

 may extend right to the top. The vlei (marsh) formation occurs 

 mainly along the streams, and includes several associations varying 

 with the degree of moisture or the aeration or otherwise of the water, 

 the drier parts showing a transition to veld. The stream and river 

 formation proper is a moist zone, like the last, but has characteristic 

 trees and shrubs. The plates accompanying the description are ad- 

 mirable pictures of the vegetation of the colony, which presents great 

 variety as one ascends from the subtropical vegetation of the coast, 

 with its mangrove vegetation, to the high altitudes of the veld and the 

 Drakensberg. — F. C. 



Wilting Coefficient of the Soil. By V. H. Blackman {Jour. EcoL 

 vol. ii. No. I, pp. 43-50). — The author presents a critical review 

 of certain recent work on the soil which promises to be of great im- 

 portance to the agriculturist and horticulturist as well as to the 

 ecologist. As is well known, owing to the physical conditions in which 

 the water is held in the soil, only a portion of the water actually present 



