INTRODUCTION. Ixi 
It is usual to rank the South-African Flora as a primary region, but here it is made 
a subregion of a region comprising tropical and South Africa and the Mascarene Islands, 
because the mountain flora of Madagascar and of tropical Africa, especially eastern, is 
largely composed of South-African types, a fact that is in a manner suppressed in 
treating them as separate regions. The same arguments apply with regard to South 
America. 
In a cartographical representation of the floras of the World it seems at first easy 
enough to indicate the centres and extensions, or isolated mountain-areas, of each, but 
the practical difficulties are insurmountable. Yet it would not be difficult to show, on 
so many maps of the world, the areas and extensions into other regions of the five 
regions proposed. There would also be space for indicating the density and limits of 
some of the leading types. This should not be done, however, in the sense of 
denominating a vast area as the “ province of the tea-tree,” the “ province of the cedar,” 
and so on, which conveys an altogether false impression ; yet unfortunately this method — 
has been continued in the latest Atlas of Plant Distribution. 
Sir Joseph Hooker, who has kindly read the proof-sheets of the foregoing pages 
and suggested many improvements, and who has consented to write a brief commentary 
on this ‘Introduction,’ does not share some of the opinions expressed by the writer, 
who himself might modify them for a primary botanical division of the world based on 
climatal conditions alone. To a great extent the facts speak for themselves, yet it is 
doubtful whether any two persons would deal with them in exactly the same manner. 
It is perhaps unnecessary to apologize for the occasional repetition of a fact or an 
argument, or for slight discrepancies in the figures cited in different places, as all persons 
engaged or interested in similar work can appreciate the difficulties of the task, and 
will excuse imperfections of such a nature. 
