I30 



NA TURE 



[July 29, 1909 



The Forests of the South Coast.— Though formerly 

 more extensive, the true forests of South Africa are 

 now practically confined to a small strip of coast-land 

 in the Knysna district. Floristically, the Knysna 

 forests are so distinct from the Cape Province that 

 Dr. Marloth has classed them (for the first time) as a 

 separate region. In this district, where the annual 

 rainfall amounts to some 36 inches, the woodland has 

 all the characters of a typical temperate rain-forest. 

 Epiphytes are common, and lianes are not infrequent. 

 Westwards the forests become more dwarfed, and 

 finally pass into the Macchia of the Cape Province. 



The Central Region. — Passing- northwards from the 

 South Coast the rainfall rapidly diminishes, and in 

 consequence the country becomes increasingly arid 

 and desert-like. Thus the Central Province (including 

 the Karroo, the Karroid uplands, and Little Namaqua- 



into grass steppes, and to the south and west into the 

 richer vegetation of the Cape Province. 



The Karroid uplands, which occupy large tracts of 

 the northern part of Cape Colony, are still compara- 

 tively little known botanically, except from the 

 collections of Thunberg, Lichtenstein, and Burchall. 

 made more than a hundred years ago. In fact, ac- 

 cording to Dr. Marloth, many parts of this region 

 have never yet been visited by botanists. 



Ecology. — The chief value of Dr. Marloth's work is 

 on the floristic side of plant geography. He has 

 travelled extensively, and, although many parts of 

 South Africa are still incompletely known botanically, 

 he has considerablv advanced our knowledge of plant 

 distribution in this part of the world. But, in addition 

 to this. Dr. Marloth has not lost sight of the ecologicaf 

 point of view. Throughout the work the dependence 



Fig. 



-Macchia from the North side of Table Mountain, showing Protea, Leucadeniron, Bruniu, &c. Reproduced from " Das Kapland, ",by 



Dr. K. Mai loth. 



land) forms a vast area, over which semi-desert 

 conditions prevail. But the only true desert in South 

 Africa is the narrow strip of coast-line known as the 

 Western Littoral. Elsewhere, the streams arising in 

 the mountains somewhat lessen the severitv of the 

 conditions, and even in the " Gouph " we can only 

 speak of a stony semi-desert. The term " Gouph," a 

 word of Hottentot origin, signifying barren, empty, 

 void, is employed to denote the most arid and desert- 

 like part of the central Karroo. The vegetation, for 

 the most part, consists of dwarfed, rounded shrubs, 

 with redyced, often ericoid leaves, and numerous 

 succulent herbs scattered between the shrubs. Here 

 and there, one or the other type of plant is so 

 dominant as to render it possible to distinguish a 

 succulent steppe from a dwarf-shrub steppe, but in 

 general they are mixed. Eastwards the Karroo passes 

 NO. 2074, VOL. 81] 



of vegetation on rainfall (which is nowhere better seen 

 than in South Africa) is emphasised, and rainfall and 

 temperature tables are introduced wherever possible. 

 One very interesting point brought out is the import- 

 ance, especially at higher altitudes, of moisture de- 

 posited on the vegetation from the thick clouds which 

 so often cover and obscure the mountain tops. An 

 apparatus for collecting the moisture precipitated 

 from clouds has been employed on Table Mountain. 

 On one occasion, during a period of six days, this 

 instrument registered a precipitation of 152 mm., 

 while an adjacent rain-gauge only recorded an actual 

 rainfall of 4 mm. The author devotes a special 

 section of more than fifty pages to the " General 

 Ecology of South African Plants." Under this 

 heading are discussed the various growth-forms found 

 in different plant formations, such as annuals, 



