lly confined to limited areas in the Himalayas, or in other cases
are found only in remote islands, as Japan or Hainan.

The distribution and affinities of the animals of continental islands thus
throws much light on that obscure subject--the decay and extinction of
species; while the numerous and delicate gradations in the modification of
the continental species, from perfect identity, through slight varieties,
local forms, and insular races, to well-defined species and even distinct
genera, afford an overwhelming mass of evidence in favour of the theory of
"descent with modification."

We shall now pass on to another class of islands, which, though originally
forming parts of continents, were separated from them at very remote
epochs. This antiquity is clearly manifested in their existing faunas,
which present many peculiarities, and offer some most curious problems to
the student of distribution.

* * * * *

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CHAPTER XIX

ANCIENT CONTINENTAL ISLANDS: THE MADAGASCAR GROUP

Remarks on Ancient Continental Islands--Physical Features of
Madagascar--Biological Features of
Madagascar--Mammalia--Reptiles--Relation of Madagascar to Africa--Early
History of Africa and Madagascar--Anomalies of Distribution and How to
Explain Them--The Birds of Madagascar as Indicating a Supposed Lemurian
Continent--Submerged Islands between Madagascar and India--Concluding
Remarks on "Lemuria"--The Mascarene Islands--The Comoro Islands--The
Seychelles Archipelago--Birds of the Seychelles--Reptiles and
Amphibia--Freshwater Fishes--Land Shells--Mauritius, Bourbon, and
Rodriguez--Birds--Extinct Birds and their Probable
Origin--Reptiles--Flora of Madagascar and the Mascarene
Islands--Curious Relations of Mascarene Plants--Endemic Genera of
Mauritius and Seychelles--Fragmentary Character of the Mascarene
Flora--Flora of Madagascar Allied to that of South
Africa--Preponderance of Ferns in the Mascarene Flora--Concluding
Remarks on the Madagascar Group.

We have now to consider the phenomena presented by a very distinct class of
islands--those which, although once forming part of a continent, have been
separated from it at a remote epoch when its animal forms were very unlike
what they are now. Such islands preserve to us the record of a by-gone
world,--of a period when many of the higher types had not yet come into
existence and when the d