56 R. H. CAMBAGE. 



of the areas in which they predominate. A study of the 

 distribution of phellandrene, as revealed by Messrs. Baker 

 and Smith's researches, points undoubtedly to the conclus- 

 ion that this constituent has been chiefly produced under 

 conditions of cold and moisture, being the principal ingre- 

 dient in the oils of such cold loving species as E. dives, 

 vitrea, Andrewsi, coriacea and stellulata, and notwith- 

 standing that it is recorded as occurring in two species 

 from the Interior, which are totally different from mountain 

 species, viz., in E. microtheca and melanophloia, its home 

 is in the Mountain Region and southern Coastal Areas of 

 South Eastern Australia. 



Phellandrene-yielding trees occur on formations from 

 basic to acid, but usually prefer those with upwards of 60% 

 silica, and generally avoid alkaline soils. 



Summary. 

 Prom a study of the physiographic, geological, and 

 climatic conditions of South Eastern Australia the follow- 

 ing general conclusions have been arrived at in regard to 

 the development and distribution of the genus Eucalyptus. 



In early Tertiary time the country had a fairly level 

 surface and a low elevation, with a mild to warm climate, 

 and the flora for two or three hundred miles inland from 

 the east coast was of a more uniform character than at 

 present. A succession of slight upheavals from the early 

 Miocene period onwards, and which culminated in the 

 Kosciusko period, created climatic conditions which pro- 

 duced a differentiation of floras on the eastern, central, 

 and western sides of the uplifted area. By investigating 

 the distribution of the Eucalypts, particularly in regard to 

 certain characters of the anthers, leaves, and essential 

 oils, some uniformity is found, within certain limits, in the 

 development of these various characters. Considering, 

 however, the great length of time the genus has been 



