Ridley .— The Distribution of Plants. 3 
The name endemic has been used for two distinct classes of plants, 
and this has led to some confusion. It is used to cover any species confined 
to a given limited area. These may be either the relics of a lost flora just 
surviving in one spot, or species evolved in one locality which have spread 
no farther. It would be advisable to have different words to express these 
two utterly distinct classes of plants. 
It is not at all difficult to distinguish to which class an endemic plant 
(in the double sense) belongs, for while the relic of a past flora has usually 
no affinity with any other in its area, the endemics of the second class 
evolved on the spot have affinities, often close, with abundance of other 
species in their locality. 
Both of these classes are well represented in the Malay Peninsula, as 
they are in most countries. 
A good example of the first class of endemic plants is that of the 
Gesneraceae of Europe, Ramondia and Haberlea occurring respectively in 
the Pyrenees and Balkan mountains. The nearest species of the order are 
the few occurring in the African mountains, but they have no affinities with 
the European species, nor have the species of northern India, but they are 
related to some Chinese and Japanese species; Ramondia is most closely 
allied to Conandron of Japan, not only in habit but in having four and 
sometimes five stamens, with lanceolate acuminate anthers, and also in the 
form of the fruit. Haberlea seems to be most nearly allied to Ramondia 
and Oreocharis of China. 
Now Clement and Mrs. Reid have shown (Pliocene Floras of the 
Dutch-Prussian Borders, ‘ Mededeel. van de Rijksopsp. van Delfstoffen ’,and 
‘ Quart. Journ. Geol.’, lxxvi. 149) that South Europe in the Lower Pliocene 
period contained a number of forms of Chinese and Japanese affinities, i. e. 
plants now confined to these regions. It seems impossible to doubt that 
these European Gesneraceae are relics of this period, or to suggest any 
other cause for their occurrence here. 
The second class of what are included popularly under the term 
4 endemics * may be exampled in the large numbers of species of Didymo- 
carpi, Sonerilas, Argostemmas, and such-like big genera in the Malay 
Peninsula, evidently evolved on the spot and not spread farther than that 
area. I do not intend to offer suggestions to account for this evolution here, 
as it would lead away from the subject of distribution. 
The Changes in Land-surface. 
These are at present and most probably always have been slow, though 
very distinct. We know that in Europe, since the appearance of flowering 
plants, there have been great changes of land and sea, and we have distinct 
traces of a former land connexion between the British Islands and North 
America in the peculiar distribution of such plants as Sisyrinchium 
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