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with reference to the Dying Out of Species . 
But if no species of the Ceylon flora, which is without doubt a very 
old one, are dying out, it is unlikely that any are dying out elsewhere. 
One may arrive at the same conclusion by studying the actual 
composition of the floras of different regions of the world, as has fallen 
to my lot to an unusual degree. Ceylon, though equatorial in position, has 
but a small flora (2,809 species) compared with the islands of the eastern 
peninsula of India, Java having, so Dr. Stapf kindly informs me, 5>°^7 
recorded to date. This has always been a difficult matter to explain, and 
the Natural Selectionists have had two rival hypotheses, which it may be 
pointed out are mutually contradictory. The first is that Ceylon has a less 
‘ tropical ’ climate than Malaya, having greater extremes of wet and dryness 
and of heat and cold. The second is that Ceylon has but a poor soil, with 
no variety in it, it being all the product of decay of gneiss and granite. 
On the first of these hypotheses the less variety in species is put down to 
greater variety in conditions, on the second to less. 
The first objection which occurs to one is that South India, with the 
same geology and a more variable climate, appears to have more species 
than Ceylon, and this is most remarkably supported by the case of the 
state of Rio de Janeiro in southern Brazil, which has just about the same 
area as Ceylon, has the same geology and soil, and, except in the narrow 
coastal belt, has a greater variety of climates, at any rate as regards heat 
and cold. The flora of Rio is something enormous, and as much richer 
than that of Java as the latter is richer than that of Ceylon. Dr. Lofgren, 
my late colleague, than whom no one better knows the flora of Brazil, 
estimates the flora of the state of Rio at 7,000-8,000 species. He calculates 
the flora of the single mountain of Itatiaya (10,000 feet), most of which 
is within this state, at 7,500 species. 
I explain this variety in the size of the floras mainly by the fact that 
the state of Rio has always, so far as geological evidence goes, been 
attached to large continental areas and is itself of enormous age. It has 
thus been open to the invasion of great numbers of foreign species, whilst 
its own mountainous configuration has tended to the development of large 
numbers of endemics within the state, just as in Ceylon every hill (and 
here also every little island off the coast) seems to have its own forms. 
Only a few days before I left Rio, Dr. Lofgren found on one of the nearer 
islands a most remarkable new species of Rhipsalis , which one could only 
describe as a pendulous shrub or tree, its stem being about four inches in 
diameter. 
From these and other similar facts I draw the conclusion that the 
number of species in a country depends upon its age from the time of its 
last submergence, and upon whether it has been attached to large areas 
with many species during most of its history, or whether it has been cut off 
at an earlier or later date. Species, or at least the majority of them, do 
