BOOKS AND CURRENT LITERATURE 21 



graphical changes. Owing to my better acquaintance with portions 

 of South Australia I will confine what I have to say to that state, par- 

 ticularly to the northern portion. 



South Australia is divided by the author into two regions by an 

 east-west line which corresponds very well to the 10-inch isohyet. In 

 the north, the "Eyre" region, the leading industry is pastoral, while in 

 the south it is agricultural. There are three leading physiographic 

 regions in the Eyre region which are the western plateau, the central- 

 eastern basin, and the south-eastern Flinders ranges. The altitudinal 

 range is approximately 4000 feet, reaching from— 39 feet of Lake Eyre, 

 the summits of the Flinders and the Musgraves, the latter of which may to 

 be over 4000 feet. Lake Eyre constitutes the receiving basin of an area 

 approximating 500,000 square miles in extent, only a small proportion 

 of which is within the state. In earlier (Cretaceous) times the drain- 

 age of this vast region is supposed to have emptied into the Southern 

 ocean through lakes Eyre, Fromme, and Torrens. By various depres- 

 sions and elevations the central portion was cut off from the sea, 

 and the ancient drainage system has lost its earlier character. The 

 amount of water that flows along the former lanes is at present of little 

 importance. 



The vegetation of the region is treated in a half-dozen paragraphs. 

 In the north-east quarter are the barest regions where long lines of 

 sand or loam ridges run approximately north and south. Normally in 

 such conditions mulga, Acacia aneura, grows sparingly on the ridges, 

 salt bushes of whatever kind occur on saline flats, and species of Euca- 

 lyptus and Acacia are to be found in the drainage channels. In the 

 west where there are sand ridges, the mulga ridges alternate with 

 spinifex flats. Here are also desert gums, Eucalyptus eudesmioides, 

 mallee and "oaks," Casurina sp. In the mountains of the west there 

 are Santalum, Melaleuca, Callitris (?), and others. The extreme south- 

 west is different from the rest of the region owing to the porous nature 

 of the limestone of which it is composed. This is the Nullarbor plain 

 (where species of salt bush dominate although in the hollows Santalum 

 and Acacia spp. occur). In the high lands of the west grasses are 

 abundant where the places are favorable (and the same could be said 

 of other similar regions, as, for example, about Copley). 



The plants of the Eyre region are subject to the most arid condition 

 to be found in Australia. The driest station, according to Taylor, is 

 Kanowana, which is east of Lake Eyre. Here the average rainfall for 

 twenty years is 4.24 inches. He finds that there is an arid "axis" 



