*5 
with reference to the Dying Out of Species . 
average climate? The composition of the flora is never absolutely the 
same round any two plants, unless they happen to be strangers growing 
in pure forest. No two samples of soil are absolutely the same. And so 
on. When one comes to the final analysis of the situation and conditions 
of any given species, one finds that no two individuals are growing under 
exactly the same conditions, and yet, for the theory of local adaptation 
to have a foothold, it is necessary that there should be only the very 
slightest differences between them, though in actual fact these differences 
are often greater between two plants of the same local endemic species 
than between two species widely separated in distance and affinity. It is 
idle playing with words to say, as do many of the supporters of Natural 
Selection, that there is something there that we do not understand, and that 
there must be differences in conditions that we cannot appreciate, and 
differences in adaptation that we do not and cannot perceive. Why should 
one endemic of Adam’s Peak be able also to survive in the widely different 
conditions of the Maskeliya valley, 2,000 feet below, and another be con- 
fined to the Peak itself, whilst a third ranges also to a second mountain 
peak ? Why should one range some distance down the Peak into different 
floras and climates, while another is confined to the summit ? Why should 
one species in the Singhe Raja forest, where on an average the conditions 
must be uniform, occupy an area of 100 metres in diameter, another one of 
i,ooo, a third one of 10,000 ? No other explanation than that which I have 
brought forward can answer questions like this, which may be put by the 
dozen, without invoking incomprehensibility, whereas that which I have 
given, that the dispersal of a species depends chiefly on its age, and that 
the endemic forms are simply young species not yet widely dispersed, 
recommends itself at once by its simplicity and wide applicability, and by 
the fact that as yet nothing can be brought up against it which is incapable 
of explanation, though doubtless, as with nearly all theories, it will prove 
insufficient later in its history. 
No evidence has ever been brought forward to prove that local species 
are adapted to local conditions ; it is simply an hypothesis, upon which it is 
impossible to explain such cases as the seven species of Castelnavia , living 
in successive cataracts in the same river, without any other forms to 
compete with, and with all the conditions of substratum, circumambient 
medium, climate, &c., absolutely the same for all, both now and in all 
previous time. 
The families Tristichaceae and Podostemaceae, as I have shown in 
another paper , 1 supply a crushing rejoinder to those who maintain that 
specific differences are due to local differences in conditions. They grow 
in such situations that there cannot be, nor ever have been, any local 
differences between them, and yet they show greater differences in morpho- 
1 On the Lack of Adaptation in the T. and P. Proc. Roy. Soc., B, vol. lxxxvii, 1914, p. 532. 
