Australian Flowering Plants. 231 



families of plants, which had been lovers of warmth and mois- 

 ture to the north of Australia, had heen driven, in part, at a later 

 stage, to the south, under the stress of severe competition and, 

 in part, by reason of their own facilities for migration. These, 

 during the various differentiations of climate, accommodated 

 themselves to the peculiar sandy soils of Australasia in the 

 temperate regions. This accommodation consisted of reducing 

 the size of the old luxuriant tree, of reducing the leaf surface, 

 or by the rejection of leaves entirely, of the utilization and 

 increase of the amount of latex, essential oils, kinos, or of 

 wax, already well developed in the families considered; of 

 the development of other special devices for checking exces- 

 sive transpiration such as the development of stomata, of stony 

 cells and of indumentum ; of lengthening the root and other- 

 wise enabling it to tap the underground supplies of water. 

 These soils were particularly adapted for the support of this 

 xerophytic vegetation inasmuch as they never became intensely 

 hard in time of drought, and although they never contained 

 a rich supply of nutriment even under conditions of heavy 

 and continued rainfall, nevertheless they ensured a scanty, but 

 sure, supply of moisture for trees or shrubby growths which 

 could develop roots long enough to tap such supply. Small 

 herbs with either thick roots, or with bulbs, such as the orchids, 

 the lilies, or certain composites could grow in most seasons by 

 storing moisture either in the thickened rootstock, or in bulbs. 

 The most remarkable point about this wonderful Australian 

 endemic flora is the focussing, segregating, or congregating, of 

 all possible types of the flowering plants on to the barren, unin- 

 viting, sandy soils during the great climatic differentiations of 

 the later and post-Cretaceous. Thus the Myrtacese in great 

 measure foresook the rich soils and the sheltered regions to 

 commence afresh on these hungry wastes ; the Proteacese, the 

 Rutacese, the Sterculiacese, and the Euphorbiacese, all in part 

 forsook the jungle for the unattractive setting of the sand- 

 stones ; the orchids descended the trees to develop numerous 

 large genera on the sandy expanses, and the epacrids, the ver- 

 benas, the labiates, and the umbellifers, became dwarfed so as 

 to flourish on the barren soils. From weakness these peculiar 

 plant assemblages became strong; they became numerous in 

 species and individuals, they became finally aggressive, but only 

 after new genera, new subtribes, new tribes, and even new 

 families, in some cases, had been developed. For it must be 

 remembered ever by the student of Australian botany, that no 

 large genus of world-wide distribution has a great develop- 



