Volume 14 Australasia - dana ward's homepage

FLORA OF ArSTE.VLTA. 871the African scirocco.. Under their action the temperature rises suddenly, bothmen and animals feel a sense of exhaustion, the vegetation droops, and if the windlasts long enough the foliage becomes blighted and withers as if frost-bitten.The rainfall diminishes rapidly from the coast towards the interior of thecontinent, and the quantity received by the inner slopes of the coast-ranges isscarcely' more than one-half that of the slopes facing seawards. Thus the fortyinches received by Sydney is reduced to less than sixteen on the western plains ofNew South ^Yales, and the supply of moisture is certainly much less in the centialregions, where the winds arrive deprived of nearly all their vapours. At thestation 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 passeswithout a single shower. Hence the greater part of Australia is too arid forEuropean settlements, or for the development of agricultural enterprise.Nevertheless,the colonists have had the immense advantage of finding a perfectly healthyclimate in all the districts where they have built their towns or established cattlefarms. Salubrity^ remains in the eyes of the immigrants from Great Britain thespecial privilege of Australia, and is regarded by them as a compensation for manymaterial disadvantages. Notwithstanding the changes required by a new sociallife, the Anglo-Saxon suffers no inconvenience by migrating to the Austral hemisphere,and the average period of existence is even said to be higher in his newhome at the antipodes.That people advanced in years here enjoy " a new lease oflife" has become a local saying in most of the settled districts.Flora of Aistrai.ia.The Australian flora presents a highly original character. Few other vegetablezones are so well defined, offering as it does a most astonishing contrast even tothat of New Giiinea, from which it is separated only by narrow and shallow waters.This originality must be explained by the long ages that have elapsed since theseparation of the southern continent. But it still seems surprising that a regionphysically so monotonous compared with Europe, and moreover of smaller extent,should jjossess so many more botanical forms. These are estimated altogether atabout 12,2-")0, of which number as many as 7,550 are quite peculiar to Australia.The only vegetable zones which present a comparatively richer or more variedflora are the southern extremity of Africa and the island of New Caledonia.There must be some coinmon cause for the extraordinary concentration of distinctspecies in these three regions of the southern hemisphere, where the floral worldappears to have increased in variety according as the lands themfelves diminishedin superficial area. Nor is it the tropical, but, on the contrary, the temperate partof all three zones that presents the greatest proportion of vegetable foi'nis ; andthese forms are again more numerous in the arid western section than in theromantic eastern division of the Australian Continent. Hence the submeigcnce ofthe land must have been greater on the side facing the Indian than on tliat turnedtowards the Pacific Ocean.B B 2