144 A RESEARCH ON THE EUCA.LYPTS OF TASMANIA 



This is also the case with A', arervula and E . paludosa 

 and whatever agreement there might have been originallv 

 between these two species they have now diverged suffi- 

 cientl}^ far to enable constant and well-defined differences 

 to be established. 



Other species, again, in which distinctive characters 

 cannot be detected between the Tasmanian and mainland 

 trees, as E. regiuin%, E. Del'egatensis, E. Ferriniana, 

 E. obliqtm, &c., may have remained constant because the 

 conditions governing their retention in both localities 

 might have undergone comparatively little alteration 

 under the new arrangement. It will be observed that 

 these are species mostly found in somewhat high altitudes, 

 and growing in both countries under similar conditions. 



Although the species supposed to be endemic in Tas- 

 mania, as E. vernicosa, E . urnigera, E. Itodwayi, E. Ris- 

 doni, &c., have no very close affinities with mainland 

 species, so far as at present known, yet it must not be 

 forgotten that each of them has its nearly related species 

 with approaching characteristics, and that they all cer- 

 tainly fall into well-defined botanical and chemical groups, 

 the peculiarities of which are now well known. 



Another point, of a chemical nature, which strongly 

 supports these suggestions, is that in the oil of only one 

 species growing in Tasmania does the aromatic aldehyde 

 aromadendral occur. This constituent is common in the 

 oils of several species in Eastern Australia, notably the 

 " Boxes," of which E. hemiphloia may be considered the 

 type. These trees are generally lowland species, E. 

 hemipJdoia particularly being a common species of the 

 plains on the eastern side of the Blue Mountains. E. 

 ohliqua is common on the mainland as well as in Tas- 

 mania, and does not appear to be so restricted to a nar- 

 row range of altitude as many species, consequently it 

 stood a better chance of survival when the subsidence took 

 place w^hich formed Tasmania, whilst the more strictly 

 lowland species were submerged and thus destroyed. 



We purpose dealing more fully with this question as it 

 affects the whole genus, at the British Association meeting 

 in Sydney in 1914. 



With reference to the oils distilled from the leaves of 

 the several species, these agree in general constituents 

 with those occurring in the oils of the members of the 

 main groups, whether from species growing in Tasmania 

 or on the mainland — of course varying in amount as the 

 botanical characters of the group become more defined. 



