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d are drifted by winds and currents to distant shores。 Pigeons； and other fruit…eating birds； are also the means of distributing plants； since the seeds readily germinate after passing through their bodies。 It thus happens that plants which grow on shores and lowlands have a wide distribution； and it requires an extensive knowledge of the species of each island to determine the relations of their floras with any approach to accuracy。 At present we have no such complete knowledge of the botany of the several islands of the Archipelago； and it is only by such striking phenomena as the occurrence of northern and even European genera on the summits of the Javanese mountains that we can prove the former connection of that island with the Asiatic continent。 With land animals； however； the case is very different。 Their means of passing a wide expanse of sea are far more restricted。 Their distribution has been more accurately studied； and we possess a much more complete knowledge of such groups as mammals and birds in most of the islands； than we do of the plants。 It is these two classes which will supply us with most of our facts as to the geographical distribution of organized beings in this region。
The number of Mammalia known to inhabit the Indo…Malay region is very considerable； exceeding 170 species。 With the exception of the bats； none of these have any regular means of passing arms of the sea many miles in extent； and a consideration of their distribution must therefore greatly assist us in determining whether these islands have ever been connected with each other or with the continent since the epoch of existing species。
The Quadrumana or monkey tribe form one of the most characteristic features of this region。 Twenty…four distinct species are known to inhabit it； and these are distributed with tolerable uniformity over the islands； nine being found in Java； ten in the Malay peninsula； eleven in Sumatra； and thirteen in Borneo。 The great man…like Orangutans are found only in Sumatra and Borneo； the curious Siamang （next to them in size） in Sumatra and Malacca； the long…nosed monkey only in Borneo； while every island has representatives of the Gibbons or long…armed apes； and of monkeys。 The lemur…like animals； Nycticebus； Tarsius； and Galeopithecus； are found on all the islands。
Seven species found on the Malay peninsula extend also into Sumatra； four into Borneo； and three into Java； while two range into Siam and Burma； and one into North India。 With the exception of the Orangutan； the Siamang； the Tarsius spectrum； and the Galeopithecus； all the Malayan genera of Quadrumana are represented in India by closely allied species； although； owing to the limited range of most of these animals； so few are absolutely identical。
Of Carnivora； thirty…three species are known from the Indo…Malay region； of which about eight are found also in Burma and India。 Among these are the tiger； leopard； a tiger…cat； civet； and otter； while out of the twenty genera of Malayan Carnivora； thirteen are represented in India by more or less closely allied species。 As an example； the Malayan bear is represented in North India by the Tibetan bear； both of which may be seen alive at the Zoological Society's Gardens。
The hoofed animals are twenty…two in number； of which about seven extend into Burmahand India。 All the deer are of peculiar species； except two； which range from Malacca into India。 Of the cattle； one Indian species reaches Malacca； while the Bos sondiacus of Java and Borneo is also found in Siam and Burma。 A goat…like animal is found in Sumatra which has its representative in India； while the two…horned rhinoceros of Sumatra and the single…horned species of Java； long supposed to be peculiar to these islands； are now both ascertained to exist in Burma； Pegu； and Moulmein。 The elephant of Sumatra； Borneo； and Malacca is now considered to be identical with that of Ceylon and India。
In all other groups of Mammalia the same general phenomena recur。 A few species are identical with those of India。 A much larger number are closely allied or representative forms； while there are always a small number of peculiar genera； consisting of animals unlike those found in any other part of the world。 There are about fifty bats； of which less than one…fourth are Indian species； thirty…four Rodents （squirrels； rats； &c。）； of which six or eight only are Indian； and ten Insectivora； with one exception peculiar to the Malay region。 The squirrels are very abundant and characteristic； only two species out of twenty…five extending into Siam and Burma。 The Tupaias are curious insect…eaters； which closely resemble squirrels； and are almost confined to the Malay islands； as；are the small feather…tailed Ptilocerus lowii of Borneo； and the curious long…snouted and naked…tailed Gymnurus rafllesii。
As the Malay peninsula is a part of the continent of Asia； the question of the former union of the islands to the mainland will be best elucidated by studying the species which are found in the former district； and also in some of the islands。 Now； if we entirely leave out of consideration the bats； which have the power of flight； there are still forty…eight species of mammals common to the Malay peninsula and the three large islands。 Among these are seven Quadrumana （apes； monkeys； and lemurs）； animals who pass their whole existence in forests； who never swim； and who would be quite unable to traverse a single mile of sea； nineteen Carnivora； some of which no doubt might cross by swimming； but we cannot suppose so large a number to have passed in this way across a strait which； except at one point； is from thirty to fifty miles wide； and five hoofed animals； including the Tapir； two species of rhinoceros； and an elephant。 Besides these there are thirteen Rodents and four Insectivora； including a shrew…mouse and six squirrels； whose unaided passage over twenty miles of sea is even more inconceivable than that of the larger animals。
But when we come to the cases of the same species inhabiting two of the more widely separated islands； the difficulty is much increased。 Borneo is distant nearly 150 miles from Biliton； which is about fifty miles from Banca； and this fifteen from Sumatra； yet there are no less than thirty…six species of mammals common to Borneo and Sumatra。 Java again is more than 250 miles from Borneo； yet these two islands have twenty…two species in common； including monkeys； lemurs； wild oxen； squirrels and shrews。 These facts seem to render it absolutely certain that there has been at some former period a connection between all these islands and the mainland； and the fact that most of the animals common to two or more of then； show little or no variation； but are often absolutely identical； indicates that the separation must have been recent in a geological sense； that is； not earlier than the Newer Pliocene epoch； at which time land animals began to assimilate closely with those now existing。
Even the bats furnish an additional argument； if one were needed； to show that the islands could not have been peopled from each other and from the continent without some former connection。 For if such had been the mode of stocking them with animals； it