INTRODUCTION. 
Geological researches 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 continents of geographers with the zoology of 
Australia and New Zealand, 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 Vespert'ilio 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 hitherto 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 productions ; the great majority of its quadrupeds being the 
Marsupiata (Kangaroos, &c.) and the Monotremata {Echidna and Ornithorhynchus), which are the very 
lowest of the Mammalia ; and its ornithology being characterized by the presence of certain peculiar 
genera, 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, Sec. 
My investigation of the natural productions of Australia induces me to believe, that at some remote 
period that country 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 thatflovs^ed 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 
