INTRODUCTION. 
xlix 
that the fauna originated within its present area, and has been always contained therein. Thus I 
take it that the fauna which characterizes the New-Zealand Region— for 1 follow Professor Huxley in 
holding that a Region it is fully entitled to be called — is the comparatively little changed relic and 
lepresentative of an early fauna of much wider range; that the characteristic fauna of the Australian 
Re b ion exhibits in the same way that of a later period ; and that of the Neotropical Region of one 
later still.” He points out that the indigenous species are with scarcely an exception peculiar to the 
country, and from every scientific point of view of the most instructive character ; and he urges the 
importance of their closest study, because the Avifauna is now being fast obliterated by colonization and 
other agencies, and with it will pass into oblivion, unless faithfully recorded by the present generation, 
a page of the world’s early history full of scientific interest. 
The biological problems which the peculiar fauna and quasi-tropical flora of New Zealand suggest 
can only be met and reasonably explained on the hypothesis of a former land-connection between these 
islands and the northern or tropical portion of Australia ; the severance, by submersion of the inter- 
T er ™g land, having taken place at a period anterior to the spread of Mammalia over this portion of 
the earth s suiface. Mr. Wallace has, I think, made it perfectly clear that this ancient land-connection 
was with North Australia, New Guinea, and the Western Pacific Islands, rather than with the 
tempeiate regions of Australia. At p. 443 of his ‘Island Life’ he gives a reduced map showing the 
depth of the sea around Australia and New Zealand, as established by the most recent soundings, 
kiom this it is manifest, as he points out, that there is a comparatively shallow sea, or, in other words, 
a submarine bank, at a depth of less than 1000 fathoms, indicating the additional land-area that would 
be pioduced if the sea-bottom were elevated 6000 feet. This submerged plateau, if we may so term 
It, piesents a remarkable conformation, extending in a broad mass westward and then sending out 
two great arms, one reaching to beyond Lord Howe’s Island, while the other stretches over Norfolk 
Island to the great barrier reef, thus forming the required connection with tropical Australia and 
New Guinea. It is argued that the ancient land-connection thus indicated, with perhaps, at a still 
more remote epoch, a connection with the great Southern continent by means of intervening lands and 
lands, will explain many of the difficult zoological problems that New Zealand presents. 
This theory, while it accounts for the introduction into New Zealand by a north-western route, 
m very ancient times, of the Struthious type of birds, from which all the known species of Dinornis 
and Apteryx may have descended, explains too the tropical character of much of the New-Zealand 
flora, Avhich is somewhat anomalous considering the temperate climate of New Zealand as we know it. 
Mr. W allace states, as the result of careful research, that there are in New Zealand thirty-eight 
thoroughly tropical genera of plants, thirty-three of which are found in Australia, and, with a very few 
exceptions, in the northern or tropical portions only. To these may be added thirty-two more genera 
of plants which, though chiefly developed in temperate Australia, extend also into the tropical or sub- 
tropical portion of it, and which, it may reasonably be inferred, reached New Zealand by the same 
loute. But to make this line of reasoning perfectly intelligible, it ought to be mentioned that the 
geological history of Australia shows it to have been for an immense period of time divided into an 
Eastern and a Western island, in the latter of which only the largely peculiar flora of temperate 
-tialia distinguished by its Eucalypti, Proteas, and Acacias — was developed, and where alone 
r maisupial Mammalia had their home. At this period, according to the above theory, New 
ealand was in connection with the tropical portion of the Eastern island alone. This important 
b eolo b ical tact will therefore account for the non-introduction into New Zealand, along with the 
9 
