Hutton.—On the Geographical Relations of the N.Z. Fauna. 235 
genera, and the members of the genus Coriphilus are said to live only on 
bananas. i 
That we should have two cuckoos which migrate regularly to other 
countries, each more than a thousand miles distant, is a fact that deserves 
special attention, for I know of no parallel case in any other part of the world, 
the distance across the Mediterranean being less than half that travelled over 
by our summer visitants. The phenomenon of a bird at a certain season of 
the year flying out to sea to an island more than a thousand miles distant is 
remarkable enough, but is rendered still more so in the case of the little 
shining cuckoo (Chrysococcyx lucidus), which is supposed to come from 
Australia, by there being no apparent necessity for it. For this bird migrates 
east and west, and not from a warmer to a colder climate, and two other 
closely allied species which inhabit Australia never leave the country at all. 
Even in the case of the long-tailed cuckoo (Hudynamis taitiensis) which 
comes to us from the equable climate of the South Sea Islands, we cannot 
suppose that its migrations are caused either by alteration of temperature or 
by want of food, and the question forces itself upon us—How could this 
habit have arisen? The only reasonable hypothesis is, I think, that at 
one time the different lands to and from which these birds fly were con- 
nected, or nearly so; that the distance between them gradually increased, 
and that the habit, so common amongst birds, of resorting each year to the 
same place to breed, was not lost but gradually merged into a regular 
migration. From this point of view the arrival of the shining cuckoo 
indicates a connection with Australia or perhaps New Guinea, while that of 
the long-tailed cuckoo indicates one with Polynesia, and it must be noticed 
that while the latter bird is identical with specimens from Polynesia, the 
former shows such differences in the colouring of the tail feathers from the 
birds inhabiting Australia that it is considered by many naturalists to be a 
distinct species. Another remarkable fact, that has been quite lately bronght 
to light, is that the shining cuckoo of the Chatham Islands is not the same 
variety as that visiting New Zealand, but is almost, if not quite, identical 
with an Australian species (C. plagosus). This curious fact proves how 
strong must be the force of habit, for these birds in their migration to and 
from the Chatham Islands must pass over, or at least in sight of New 
Zealand, but instead of stopping, after a journey of 1,400 miles, they continue 
on for 450 miles more, until they reach the little island that they have 
selected as their home. 
A more difficult fact to account for is the presence of different species of 
grass-bird (Spheneacus) in both Australia and New Zealand, for this bird has 
such feeble powers of flight that it could not cross a river, and must almost of 
necessity have travelled by land. It must, however, be noticed that this 
