Ridley . — On Endemism and the Mutation Theory. 559 
persisting on the wet limestone rocks, surrounded by a geologically modern 
rain-forest flora, which has swamped it everywhere but on the summit 
where the big rain-forest trees could not grow. 
‘ Endemic species confined to small areas are really species in the earlier 
stages of spreading, and, given time enough, they might ultimately be found 
covering large areas. Endemic species begin as VR in some given country, 
and gradually extend their area, passing upwards through the stages R, RR, 
RC, &c.’ 1 
This general statement could only be correct if these endemics were 
found to have all arisen from other species now in the island. Dr. Willis gives 
a list of genera containing endemic species, but omits all the endemic mono- 
typic genera, Trichadenia , Julostyles , Pity rant he, Pseudocar apa, Glenniea , 
Pericopsis , Schizostigma , and many others, and does not mention the fact 
that a large number of the endemic species are the only ones of their genus 
in the island. Elow can these be species in the early stages of spreading ? 
Furthermore, most of. them are rare, and some almost, if not now quite, 
extinct. 
On examining the affinities of these endemics we find that a very con- 
siderable proportion are Malayan. Now the connexion of the Malay 
region with Ceylon must have been at a very long distance of time ago. 
The genera containing endemics are nearly all rain-forest country plants, 
and appear to be now nearly confined to the wettest region of Ceylon. 
Exactly what we should expect if there was at a very long distance of time 
a land connexion with the tropical rain-forest'region, which being destroyed, 
this very old flora persisted in the wet mountain regions till a large por- 
tion of it was destroyed by man, directly or indirectly, by felling the forests 
and causing diminution of the rainfall over a large area. This will account 
for the state of the flora and its constituents, but Dr. Willis’s theory 
will not. 
‘ Ceylon, though equatorial in position ’ (which it is not), ‘ has but a small 
flora (2,809 species) compared with the islands of the eastern peninsula 
of India. . . . This has always been a difficult matter to explain, and the 
Natural Selectionists have had two rival hypotheses. . . . The first is that 
Ceylon has a less “ tropical ” climate than Malaya, having greater extremes 
of wetness and dryness and of heat and cold. The second is that Ceylon 
has but a poor soil, ... it being all the product of the decay of gneiss and 
granite.’ 2 I do not see how these two theories are ‘ mutually contradic- 
tory nor do I know who the Natural Selectionists are who have made 
these suggestions. It is obvious to every one who has at all examined the 
flora of Ceylon, that, as already pointed out, an immense quantity of the 
original flora has been destroyed by man but replaced by imported weeds 
which largely bulk in the VC’s of Trimen’s Flora. This destruction was 
1 Ann. Bot., 1 . c., p. 5. 2 1 . c., p. 21. 
