VI 
PREFACE. 
rational to suppose that an explanation is to t ,e 
found, either in the condition of the earth’s suf' 
face, climate or change of the seasons, tl' e 
supply of food, or some other cause depending 
on local peculiarities. 
It is by these local Faunas that the Geogrn- 
phical distribution of animals has been of lat e 
so successfully cultivated, and a few of the laW 8 
which govern them ascertained. It has been 
found that similar climates however widely 
separated from each other, are inhabited hy 
similar animals, or animals of similar habits- 
Thus it is that the Himalaya mountains of Asia* 
which rise from the plains of the torrid zon e 
through every belt of climate, to regions of p ef ' 
petual snow, have representatives of almost 
every living class of creatures. This is of cours e 
considerably modified by the character of tl> e 
surrounding country. If the zones of cliinat e 
follow closely on each other, each becomes varie- 
gated by the encroachments of the production 8 
of those above and below ; the nature also 
the soil considerably modifies it, such as hi^ 
or plain or swamp. But there are phenomena 
regarding the distribution of animals which 
present seem inexplicable, such is the congre- 
gation of peculiar classes of animals in particula 1 
districts, beyond which they may almost be said 
to be extinct, a remarkable instance of whie * 1 
is to be found in the zoology of New Sou ^ 1 
Wales. 
