564 DEVELOPMENT OP THE N.O. MYRTACE^E, 



moderate shelter, in the recently formed plateau-province of 

 South-eastern Australia. E. Perriidana, E. umigera, E. alpina, 

 E. Gunnii, and E. vernicosa have evolved on the wind-swept and 

 snow-laden plateaus to the south; while E. viridis, E. Morrisii, 

 E. platyphylla, E. oleosa, and E. dumosa are a response to the hot 

 and subarid to arid portions of the continent. E. rostrata has 

 spread across Australia by creeping along watercourses, and thus 

 defying the surrounding desert-conditions; while E. coruuta, E. 

 gomphocephala, E. cosmophylla, E. macrocarpa, E. piriformis, E. 

 ccesia, E. megacarpa, E. fcecunda, E. loxophleba, E. diversicolor, 

 E. redunca and others, occur in Western Australia, and are 

 found neither in Northern nor Eastern Australia. In most 

 cases, the peculiarities of these various assemblages are suggestive 

 of a response to xerophytic conditions. This is, however, not 

 applicable to the famous globulus-group, whose youthful stages 

 indicate an immediate ancestor which flourished in cool, temper- 

 ate, moist, shady and moderately sheltered situations. In a 

 word, so effectively has the general development progressed, and 

 so universally have the intermediate or connecting forms been 

 stamped out, that no systematist can state from which group 

 either the Eucalypts or the Porantheras have sprung. Neither 

 can the origin of the globulus-growp be traced back more than 

 one step. All that is known is, that the globulus-group is 

 relatively young, so also the Eucalypts, while the Corymbosse are 

 old. 



Angophora presents a peculiar problem to the student of distri- 

 bution. Indistinguishable from the Coryinbosae Eucalypts, except 

 for the coherence of the petals to form an operculum to the 

 unopened flower, it occurs only in the milder extratropical 

 portions of Eastern Australia ; its anthers are parallel, and 

 they open in longitudinal slits ; its stamens are not brightly 

 coloured ; its bark, with one exception, is rough ; its leaves are 

 mostly opposite and sessile ; with one exception, the soils it 

 seeks, are extremely sandy, porous, and lacking in fertility ; 

 and the distribution of the species is exceedingly limited, being 

 confined, with one exception, to small patches of barren sand- 

 stone. Such are A. cordifolia, a stunted type, confined to the 



