Over the vast area of more than five hundred and twenty thousand square miles occupied by the Northern Territory there are, as might be expected, great variations in regard to climate and natural features. Whilst this is so, it is, on the other hand, possible to divide it into three main parts, a Southern Central plateau, gradually rising from the lowlands of Lake Eyre to the Macdonnell Ranges. A Northern Central depression, in the form of a great basin, margined to the north, east and west by the Coastal Ranges, and lastly a fringe of coastland between the latter and the sea.

The first two of these, again, agree in all essential features. They have the same hot, dry climate, sparse vegetation of gum trees, Mulga scrub, Hakeas and porcupine-grass. Every now and then, but very rarely, the vegetation may be a little more luxuriant, in spots such as Palm Creek in the Macdonnell Ranges where a solitary colony of Fan palms (Livistonia mariœ) has managed to survive, and where groups of graceful Cycads grow in crevices amongst the rocks. Away, however, from the Ranges the country is more or less arid. The soil is dry and sandy with tufts of pale, withered grass that grow so far apart from one another that you can easily count them. It is wonderful how long the grass keeps its moisture. It must have learned the habit of throwing its roots down to a great depth.