BOTANICAL AND CHEMICAL CHARACTERS OF EUCALYPTS. 109 



Eucalypts, published in 1902, the ' Bloodwoods ' are placed as the oldest 

 section of the whole genus ; trees having the venation of the ' Blood- 

 woods ' occur more plentifully in West Australia and sweep right round 

 the north of the continent to one or two outliers in the south-eastern 

 corner of New South Wales ; all have red timber. 



Following the evolution along this geographical line, the different 

 groups are met with in succession and it is apparent that in Victoria 

 white timbers predominate to the almost entire exclusion of redwoods. 

 On crossing to Tasmania, this distinction is more pronounced, not a 

 single redwood Eucalypt occurring there. In Tasmania again not a 

 single representative of the important group known commonly as ihe 

 ' Boxes ' is to be found. 



The venation is also correlative and so are the essential oils and the 

 kinos. Thus the greatest affinity of Tasmania Eucalypts is with those 

 of Victoria and, along with those of Victoria and New South Wales, 

 they are the more recent of the genus. 



The two species, E. Gunnii and E. Perriniana, of" the highest 

 altitudes of Tasmania and Victoria, show specifically remarkable simi- 

 larities in botanical and chemical characters, although growing so far 

 apart, the sea also intervening. 



The oil constituents of these two species vary considerably in both 

 localities but are practically constant in a given species, whether it gi'ow 

 in the higher portions of New South Wales or in Tasmania. The 

 somewhat large amount of the ester butylic-butyrate in the oil of E. 

 Perriniana, together with an increased amount of cineol and a com- 

 parative absence of phellandrene, seem to be distinguishing chemical 

 features in the case of these two closely agreeing species, which, judging 

 both from botanical and chemical evidence, cannot be identical. 



As this land separation has now existed through a long period of 

 time, some of the species common to both localities show a slight 

 variation or departure from the type. E. amygdalina of Tasmania 

 differs from the mainland variety in its larger leaves and fruits and in 

 chemical constituents; also, E. acervida is most probably a changing 

 form of E. paludosa, E. phlebophylla a divergence from E. coriacea 

 and E. virgata from E. Sieberiana. 



The majority of the Eucalyptus species of Tasmania, therefore, 

 show a marked correlation with those of South-Eastern Australia ; this 

 correlation is pronounced in the case of species growing at the lower 

 as well as the higher levels. 



It is generally recognised that trees descend to lower levels as the 

 climate changes to colder conditions ; the Eucalypts are no exception 

 to this rule. E. regnans is found in Victoria growing at fairly high 

 elevations, whilst in Tasmania it flourishes almost at the sea-level; 

 E. Delegatensis is rarely found below 4,000 feet in Victoria and New 

 South Wales, yet grows between 2,000 and 3,000 feet in Tasmania. 



The Cotyledons and Seedling Leaves of the Eucalypts. 

 By CuTHBERT Hall. 



The study which I have recently published (24) disclosed, as the 

 result of a comparative consideration of a large number of species, that 



