BOTANY. 39i 



At or near the Tropic of Capricorn may be fixed the 

 boundary line which separates the two above-named great 

 Floras ; south of it lying the extra -tropical portion, to 

 which the term " South " Africa is here applied, and north 

 of it, as far as the Tropic of Cancer, the inter-tropical 

 portion, termed " Tropical " Africa. Extra-tropical North 

 Africa belongs to the Mediterranean Region, and there- 

 fore needs no further comment here. 



A very interesting Sketch of the Floi'a of South Africa 

 was published by Mr. Harry Bolus, F.L.S., in the ' Official 

 Handbook of the Cape of Good Hope' for 1886. The 

 extreme richness of the Flora and the large proporton of 

 peculiar types are there pointed out, it being estimated 

 that in this respect South Africa falls very little short of 

 Australia, with its far greater area. Mr. Bolus thinks the 

 following may be the proximate causes of this great 

 richness : — 



(1.) The meeting and partial union of two (perhaps 



three) distinct Floras of widely different age and 



origin. 

 (2.) A highly diversified surface of the land and of 



soil. 

 (3.) A climate with much sunlight (or little cloud) ; a 



condition which seems everywhere favourable to 



the multiplication of forms. 



South Africa is regarded as divisible into five natural 

 Regions ; though in any comprehensive scheme they 

 would rank better as Sub-regions only. 



The South-Western Region is an angular littoral 

 strip some fifty to eighty miles wide, extending from near 

 Oliphant's River to Van Staden's Berg, near Port Elizabeth. 

 The rainfall is generally scanty, the greater portion falling 

 from May to August, and the surface of the country 

 highly diversified. The prevailing feature of the vegeta- 

 tion is the abundance of low-growing shrubs called the 

 " bush," with small leaves, generally of sombre aspect, 



