142 



NATURAL HISTORY OP THE [chap, tx 



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 b}' studyin^^ the 

 species which are found in the former district, and also in 

 some of the islands. Now, if we entirely leave out rif con- 

 sideration the bat.s, which have the power of lliglit, there 

 are still forty-eight species of mammals common to the 

 Malay peninsula and the three large islands. Among these 

 are seven Quadrumana (apes, iiifuskeys, and lemurs), animals 

 wlio pass their whole existence in forests, who never smm, 

 and who would be quite unable to traverse a single mile of 

 sea ; nineteen Carnivora, some of which no doubt njight 

 cross by swimming, but we cannot suppose so large a 

 number to have passed in this way across a strait wliich, 

 except at one point, is from thirty to fifty miles wide ; and 

 five hoofed animals, including tlie Tapir, two species of 

 rhinoceros, and an elephant. Besides these tliere are 

 thirteen Bodents and four Insectivora, including a shrew- 

 mouse and sLx squirrels, whose unaided passage over 

 twenty miles of sea is even more inconceivable than that 

 of the lai^er animals. 



But wheu we come to the cases of the same species 

 inhaliiting two of the more widely separated islands, the 

 difhculty 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 ii absolutely cer- 

 taui that tliere has been at some former period a connexion 

 ' between all these islands and the main land, and the fact 

 that most of the animals common to two or more of them 

 show little or no variation, but are often absolutely identi- 

 cal, indicates that the separation must have been recent in 

 a geological sense ; that is, not earlier than the Kewer 

 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 islaruh coiild not have been 



