466 



K. Gunnii, but xylogically and chemically the relationship 

 cannot be established with that Tasmanian species. 



The salient species of this group is the "Murray Red 

 Gum," E. rostrata, a characteristic feature on all the water- 

 ways in the State. 



The group known as "'Boxes," so prominent in New- 

 South Wales, is also not wanting in South Australia, and 

 E. Woollsiana and E. albens are good representatives. 



The"Stringybark" group has likewise a good representative 

 in E. obliqua, which is restricted to the South-eastern ranges y 

 where it is found growing along with the other "Stringy- 

 barks," E. capitellata and E. macrorhyncha. 



Such distinctive groups as "Peppermint" and "Iron- 

 bark" are quite absent — not a single species of either being 

 so far recorded. 



Of these groups, the best timber trees are E. rostrata, 

 E. obliqud, E. leucoxylon, E. microtheca, and E. largi- 

 florens; while the best oil-producing species are E . cneo?i folia, 

 E. odorata, and E. oleosa. 



It thus appears that these are the best of the South 

 Australian species of Eucalypts for re-afforestation, or for 

 commercial oil-production. 



The following list gives the approximate number of 

 representatives of the several groups: — Striugybarks, 3; 

 Gums, 9 ; Mallees, 11 : Boxes, 8 : Ironbarks, : Blood- 

 woods, 0; Peppermints, 0; Ashes, 0. 



(b ) Chemical. 



The chemical investigation of the Essential oils of a 

 number of species which are considered in this paper for the 

 first time shows that, taken as a whole, general agreement 

 may be traced between the constituents of these species and 

 those of certain groups growing in the eastern portion of the 

 continent. None of them, however, is referable to the large 

 group of phellandrene-bearing oils which occurs so plentifully 

 in the highlands of New South "Wales and Victoria, and in 

 Tasmania. The characteristic constituent of the oils of these 

 latter species is the ketone .piperitone, and in no case was this 

 constituent detected in the oils of the ten species now investi- 

 gated for South Australia. The distinguishing constituent 

 most frequently occurring in these oils is aromadendral — the 

 high-boiling laevorotatory aldehyde so frequently found irt 

 the oils of the "Mallees" and in those species allied to them, 

 as, for instance, the typical "Boxes" (E. hemiphloia, E. 

 albens, etc.). 



The quantity of oil obtained from the leaves of some of 

 the species described is particularly small, and in no instance 



