Angophora lanceokata, Cav., and was found to contain identical constituents to 

 those obtained from the 'Bloodwoods" just .mentioned. The sesquiterpene 

 (aromadendrene) which occurs in some quantity in all this group of Eucalypts, 

 was also present in the oil of Angophora lanceolata, as it gave the characteristic 

 colour reaction for that constituent with bromine. (For the essential oils of 

 the Angophoras, see paper by one of us, Roy. Soc., N.S.W., Aug., 1913.) 



In August, 1896, a paper was read by one of us (Roy. Soc., N.S.W.) on a 

 crystalline substance obtained from the exudation, or kino, of the " Red Gum " 

 (E. calophylla), sent to the Museum by the Bureau of Agriculture, Western 

 Australia ; this substance was named aromadendrin. In the description of a 

 new Angophora (A. melanoyxlori) , by one of us (Proc. Linn. Soc., N.S.W., 1900), 

 the announcement was made that the kino of this tree contained aromadendrin, 

 it being chemically identical with that described from E. calophylla. The 

 chemical evidence relating to the affinity of these genera which has since 

 accumulated, shows the connection to be somewhat complete. 



Assuming the Angophora to be the older genus, we have endeavoured 

 to formulate, on data similar to the above, a table or " tree," showing the supposed 

 line of origin of the various groups of Eucalypts from the apparent initiation 

 of the Genus. The table will be found at the end of this article, and a map of 

 Australia indicating more fully the territorial distribution in connection with 

 this evolution table is also added. The table includes the majority of the 

 species of Eastern and Southern Australia, but when those of Northern and 

 Western Australia shall have been more fully investigated on similar lines, a 

 more complete tabulation will be possible, as then, no doubt, many of the 

 connecting links which are at present felt to be wanting, will be forthcoming. 

 We do not think that the investigation of those species will interfere materially 

 with the main principle of evolution as here laid down. 



Proceeding from the " Bloodwoods," it is possible, from the evidence 

 available, that the line of descent was through E. saligna and E. botryoides, the 

 venations (plate in), together with the chemical constituents of the oils, being 

 very closely allied to those of the ." Bloodwoods." In the oil of E. saligna 

 cineol is making its appearance, for, although present but in small amount, it 

 could be detected quite satisfactorily. 



If botanical features are considered in conjunction with those of the 

 chemical, it is seen that as the characteristic constituents of the oils vary in 

 amount and change their character, so do the trees form well-defined groups. 



For instance those seceding from the " Bloodwoods " apparently pass 

 in three directions, one through the " Stringybarks " to the group of " Pepper- 

 mints," another through the " Ironbarks " to that large group which includes 

 the cineol-pinene oils generally, or those in which the terpene phellandrene is 

 absent, and thirdly through one section of the " Stringybarks " particularly 

 E. obliqua> to the other large group which includes the typical " Boxes " and 

 their associated " Malices." The Genus may thus be considered as embracing 

 four large groups which may be indicated, chemically, as follows : 



(a) Those yielding oils consisting largely of the terpene pinene ; either 



dextro-rotatory or laevo-rotatory. 



(b) Those yielding oils containing varying amounts of pinene and cineol, 



but in which phellandrene is absent. 



(c) Those yielding oils in which aromadendral is a characteristic constituent, 



and phellandrene usually absent. 



(d) Those yielding oils in which the terpene phellandrene is a pronounced 



constituent, with piperitone mostly present. 



50068 B 



