CHAP. XVII.] 
BORNEO AND JAVA. 
355 
two others, Pityriasis, an extraordinary bare-headed bird 
between a jay and a shrike, and Carpococcyx, a pheasant-like 
ground cuckoo formerly thought to be peculiar, are said to have 
been discovered also in Sumatra. 
The insects and land-shells of Borneo and of the surrounding 
countries are too imperfectly known to enable us to arrive at 
any accurate results with regard to their distribution. They 
agree, however, with the birds and mammals in their general 
approximation to Malayan forms, but the number of peculiar 
species is perhaps larger. 
The proportion here shown of one-third peculiar species of 
mammalia to about one-fifth peculiar species of land-birds, 
teaches us that the possession of the power of flight only affects 
the distribution of animals in a limited degree, and gives us 
confidence in the results we may arrive at in those cases where 
we have, from whatever cause, to depend on a knowledge of the 
birds alone. And the difference we here find to exist is almost 
wholly due to the wide range of certain groups of powerful flight 
— as the birds of prey, the swallows and swifts, the king-crows, 
and some others; while the majority of forest-birds appear to 
remain confined, by even narrow watery barriers, to almost as 
great an extent as do the mammalia. 
The affinities of the Bornean Fauna . — The animals of Borneo 
exhibit an almost perfect identity in general character, and a 
close similarity in species, with those of Sumatra and the Malay 
Peninsula. So great is this resemblance that it is a question 
whether it might not be quite as great were the whole united ; 
for the extreme points of Borneo and Sumatra are 1,500 miles 
apart — as far as from Madrid to Constantinople, or from Bombay 
to Kangoon. In this distance we should expect to meet with 
many local species, and even representative forms, so that we 
hardly require a lapse of time sufficient to have produced specific 
change. So far as the forms of life are concerned, Borneo, as an 
island, may be no older than Great Britain ; for the time that has 
elapsed since the glacial epoch would be amply sufficient to pro- 
duce such a redistribution of the species, consequent on their 
mutual relations being disturbed, as would bring the islands into 
their present zoological condition. There are, however, other 
A A 2 
