INTRODUCTION. 
Geological investigations into the structure of the globe show that 
a succession of physical changes have modified its surface from the 
earliest period up to the present time, and that these changes have 
been accompanied with variations not only in the phases of animal 
and vegetable life, but often in the development also of organization ; 
and as these changes cannot be supposed to have been operating 
uniformly over the entire surface of the globe in the same periods 
of time, we should naturally be prepared for finding the now existing 
fauna of some regions exhibiting a higher state of development than 
that of others ; accordingly, if we contrast the fauna of the old con- 
tinents of geographers with the zoology of Australia and New Zea- 
land, we find a wide difference in the degree of organization which 
creation has reached in these respective regions. In New Zealand, 
with the exception of a Vespertilio and a Mus, which latter is said 
to exist there, but which has not yet been sent to this country, the 
most highly organized animal yet discovered, either fossil or recent, 
is a bird ; in Australia, if compared with New Zealand, creation 
appears to have considerably advanced, but even here the order 
Rodentia is the highest in the scale of its indigenous animal pro- 
ductions ; the great majority of its quadrupeds being the Marsu - 
piata (Kangaroos, &c.) and the Monotremata ( Echidna and Orni- 
thorhynchus ), which are the very lowest of the Mammalia. The 
ornithology of Australia is characterized by the presence of certain 
peculiar genera, the Talegalla , Leipoa and Megapodius ; birds which 
do not incubate their own eggs, and which are perhaps the lowest 
representatives of their class, while the low organization of its botany 
is indicated by the remarkable absence of fruit-bearing trees, the 
Cerealia , &c. 
My investigation of the natural productions of Australia induces 
me to believe, that at some remote period it was divided into at least 
two portions, since, with a few exceptions, I find the species inhabiting 
the same latitudes of its eastern and western divisions differing from, 
but representing each other. Some writers, Captain Sturt and Mr. 
Jukes, e. g. are of opinion that its subdivision was even greater, and 
that the sandy deserts now met with in the interior were formerly 
the beds of the seas that flowed between the archipelago of islands 
of which they suppose it to have been composed. In a valuable 
paper by Mr. Jukes, entitled ‘ Notes on the Geology of the Coasts 
of Australia,’ read at the meeting of the Geological Society on the 
17th of November 1847, that gentleman stated, that “ The eastern 
coast is occupied by a great range of high land, appearing like a 
continuous chain of mountains when seen from the sea, and rising 
in several places to 5000 feet or more above the sea-level. This 
chain has an axis of granite, with occasional large masses of green- 
