72 THE WORLD OF LIFE 



CHAP. 



I will now briefly discuss the various interesting questions 

 raised by a consideration of these tables. 



It is, I believe, still a very common opinion among 

 botanists that the wonderfully diversified flora of the Cape 

 Region of South Africa is the richest in the whole world in 

 so limited an area. This is partly owing to the fact that 

 such a large proportion are beautiful garden plants, which 

 for sixty years, from 1775 to 1835, poured in a continued 

 stream into Europe and seemed almost inexhaustible. The 

 wonderful group of heaths, of which there are about 350 

 species, all beautiful and many among the most exquisite of 

 flowers ; the almost equally numerous pelargoniums, the 

 brilliant ixias, gladioli and allies, the gorgeous proteas, the 

 wonderful silver-tree, the splendid lilies and curious orchises, 

 the endless variety of leguminous shrubs, and the composites 

 including the everlasting flowers, together with hundreds of 

 other delicate and beautiful little greenhouse plants, formed 

 an assemblage which no other country could approach. Rich 

 as it is, however, there is now reason to believe that West 

 Australia Swan River Colony in its original restricted 

 sense is quite as productive in species, while evidence is 

 slowly accumulating that many parts of the tropics are really 

 still more productive. 



The first to be noticed of these rich tropical areas of 

 small extent is the island of Penang in the Straits of 

 Malacca, which, though only 106 square miles in area, 

 contains 1813 species. Sir Joseph D. Hooker, in his Sketch 

 of the Flora of British India (1906), terms this " an astonish- 

 ing number of species," and remarks on the large proportion 

 which are arboreous, and of the altitude of the island being 

 only 2750 feet. Here, therefore, in an area considerably less 

 than that of the Cape Peninsula, the species are actually 

 more numerous, and this was evidently a new and astonish- 

 ing fact to one of the greatest of our living botanists. 



But the somewhat larger island of Singapore shows us 

 that this amount of productiveness is quite normal ; for 

 though it is 206 square miles in extent, it is almost flat, the 

 greatest elevation being only a few hundred feet. A large 

 part of the surface is occupied by the town and suburbs, 

 while the original forest that covered it has been almost all 



