182 
and Marten have become very rare, and the Badger and Otter are 
now unknown in many localities where they were once common, 
khe box has been exterminated and renewed again and again in 
some localities, foreign importations having sometimes finnished 
the fresh supplies. All these changes have arisen from the 
destruction of the forests, which at one time extended over vast 
h'acts of country, but are now replaced by cultivated fields. There 
IS, however,'^' one animal, probably itself an introduced species, 
which has been almost exterminated during the present century in 
the struggle for existence, brought about by the appearance on the 
scene of a foreign rival. I refer to the old English Black Eat 
(Mils rattus). I do not for one moment suppose that anybody 
would think of introducing the Biwvn Eat (Mus decumanus) to a 
locality where it was unknown ; and yet it lias spread wherever 
commerce has extended, and devastation has marked its course. 
Sw'arming on shipboard it has been transported to distant climes, 
climate seeming to be a matter of indifference to it, and escajiing 
perhaps from ■wrecks, has established itself even on uninhabited 
islands. ^ Our comparatively harmless Black Eat has probably 
fallen a victim to it, and it has been known to dislodge the Eabbits 
and Puffins from their breeding places on the shore. Fierce in 
disposition, omnivorous in appetite, and prolific bejmnd conception, 
it soon succeeds in establishing itself, and works incalculable 
mischief wherever it appears. At our antipodes, having it is 
thought by many already destroyed the native Eat or Kiore, it 
ascends the trees, aided by the numerous climbing plants, and, 
feeding upon the eggs and jmung of the forest birds, reduces to 
silence the groves once resonant with the music of the songsters 
with which they were fiUed.t And thus the Eat is materially 
assisting in bringing about tlie destruction of the remarkable fauna 
of the islands of the Eew Zealand group as doubtless of many 
others in the Southern Hemisphere. 
* Professor Boyd Dawkins tells me that he has never found or identitied 
tlie remains of Mus rattus in a fossil state, or in any refuse-heap of Roman 
age, or in Neolithic or Bronze-age tombs or dw'ellings. It is probable that 
this species was in Britain in the Norman age ; also that 31. decumanus was 
not in Britain in the reign of William and Mary. 
t Trans. New Zealand Institute, ly(J9, p. ‘29P. 
