FLORA OF AUSTRALIA. 371 



the African scirocco. Under their action the temperature rises suddenly, both 

 men and animals feel a sense of exhaustion, the vegetation droops, and if the wind 

 lasts long enough the foliage becomes blighted and withers as if frost-bitten. 



The rainfall diminishes rapidly from the coast towards the interior of the 

 continent, and the quantity received by the inner slopes of the coast-ranges is 

 scarcely more than one-half that of the slopes facing seawards. Thus the forty 

 inches received by Sydney is reduced to less than sixteen on the western plains of 

 New South Wales, and the supply of moisture is certainly much less in the central 

 regions, where the winds arrive deprived of nearly all their vapours. At the 

 station of Charlotte Waters, in the heart of the continent (26^ 29' south latitude), 

 the mean annual discharge is only five inches, and at times a whole year passes 

 without a single shower. Hence the greater part of Australia is too arid for 

 European settlements, or for the development of agricultural enterprise. Never- 

 theless, the colonists have had the immense advantage of finding a perfectly healthy 

 climate in all the districts where they have built their towns or established cattle 

 farms. Salubrity remains in the eyes of the immigrants from Great Britain the 

 special privilege of Australia, and is regarded by them as a compensation for many 

 material disadvantages. Notwithstanding the changes required by a new social 

 life, the Anglo-Saxon suffers no inconvenience by migrating to the Austral hemi- 

 sphere, and the average period of existence is even said to be higher in his new 

 home at the antipodes. That people advanced in years here enjoy " a new lease of 

 life " has become a local saying in most of the settled districts. 



Flora of Australia. 



The Australian flora presents a highly original character. Few other vegetable 

 zones are so well defined, offering as it does a most astonishing contrast even to 

 that of New Guinea, from which it is separated only by narrow and shallow waters. 

 This originality must be explained by the long ages that have elapsed since the 

 separation of the southern continent. But it still seems surprising that a region 

 physically so monotonous compared with Europe, and moreover of smaller extent, 

 should possess so many more botanical forms. These are estimated altogether at 

 about 12,250, of which number as many as 7,550 are quite peculiar to Australia. 

 The only vegetable zones which present a comparatively richer or more varied 

 flora are the southern extremity of Africa and the island of New Caledonia. 

 There must be some common cause for the extraordinary concentration of distinct 

 species in these three regions of the southern hemisphere, where the floral world 

 appears to have increased in variety according as the lands themselves diminished 

 in superficial area. Nor is it the tropical, but, on the contrary, the temperate part 

 of all three zones that presents the greatest proportion of vegetable forms ; and 

 these forms are again more numerous in the arid western section than in the 

 romantic eastern division of the Australian Continent. Hence the submergence of 

 the land must have been greater on the side facing the Indian than on that turned 

 towards the Pacific Ocean. 



