108° REPORT—1868. 
Wherever upon islands contiguous to each other or to a continent animals or plants 
of the same or closely analogous descriptions are observed, it will be found, upon 
investigation, that the sea between them is shallow; and that where a deep sea 
divides islands from each other, there entirely different types will be found. An 
upheaval of only 50 fathoms would make dry land of the whole sea intervening 
between Borneo, Java, and Sumatra, and the mainland of Malacca and Siam, while 
the 100-fathom line of soundings includes the Philippines and other groups; from 
which fact he argues the comparatively recent submergence of this part of Asia. 
He then adduced a variety of arguments from the zoological world, instancing 
examples both of Carnivora and Ruminantia which are common to the islands 
named and to Southern Asia, while they are totally unknown to Australia, yet 
which could never have reached the islands of the western section from the’ main- 
land of Asia so long as the ocean retained its present configuration. 
A few anomalies are observable in the Philippines, which could sufficiently be 
accounted for by the more remote period at which they were cut off from Asia, as 
indicated by the greater depth of the intervening ocean. The islands, from Celebes 
and Lombok eastward, present many of the characteristic features of the Austra- 
lian region, as indicated by the shallow sea and the similarity of fauna and flora 
between the eastern section of the Indo-Australian archipelago and Australia, 
while the strait, barely 15 miles wide, between Bali and Lombok, marks the dividing- 
line between the Asian and Australian kingdoms of natural history. From these 
various data a general conclusion may be drawn, that all the islands eastward of 
Borneo and Java formed part of an Australian or Pacific continent, from which 
they were separated at a period not merely long antecedent to the submergence of 
the adjacent portion of the Asiatic continent, but promenly, long before any portion 
of South-eastern Asia emerged from the waves; basing this conclusion upon the 
comparatively recent geological formation of Jaya and Borneo, and on the great 
depth of the sea between Borneo and the eastern section of the archipelago, which 
pointed to a very long period during which the two continents of Asia and Australia 
were widely separated. 
Particular attention was called to the fact that the division of the archipelago 
now pointed out did not correspond to any physical or climatal divisions; for the 
volcanic band runs through both sections, and the climates of Borneo and New 
Guinea are very similar; yet in spite of these, which are usually deemed the neces- 
sary conditions for ensuring similarity of animal life, the most striking contrast 
' between them respectively at once forces itself even upon the most unobservant 
traveller. The differénes between these two sections of the archipelago was further 
illustrated by showing what would be the consequence of the two continents of 
Africa and South America becoming joined in the course of ages by the slow up- 
heaval of the Atlantic bed, and the erosive agency of rivers on either continent. 
If, then, a renewed period of upheavals occurred, islands would have been formed 
similar to those of the Indo-Australian archipelago, yet equally dissimilar as to 
natural history. The paper concluded by urging upon naturalists increased devo- 
tion to that science, as tending to throw light upon many of the most recondite 
questions of the earth’s previous history. 
On the Geographical Distribution of Animal Infe. By A. R. Wattace. 
The author called attention to the six geographical regions established by Dr. 
Selater (Proc. Linn. Soc., Feb. 1858) for ornithology—yviz., 1st, the Neotropical, 
comprising South America and the West Indies; 2nd, the Nearctic, including the 
rest of North America; 3rd, the Palearctic, composed of Europe, Northern Asia 
to Japan, and Africa, north of the Desert; 4th, the Ethiopian, which contains the 
rest of Africa and Madagascar; 5th, the Indian, containing Southern Asia and the 
western half of the Malay archipelago; and 6th, the Australian, which comprised 
the eastern half of the Malay Islands, Australia, and most of the Pacific Islands. 
It was stated that these regions would apply almost equally well to mammalia, 
reptiles, land-shells, and insects; but there were some exceptional cases, which 
it had been thought would render these regions inapplicable to zoology gene- 
rally. These exceptional cases were—lIst, that the fatenakiineld of Japan are 
Palearctic, agreeing with the birds, &c.; but the snakes are altogether Indian, as 
