5 
SPECIFIC DISTINCTIONS—ASPECT OF THE TREE 
record the results of their laboratory work in distilling, analyzing, and standard¬ 
izing the oils from a very large number of the species. They also name and 
describe several species that had previously been either overlooked or wrongly 
included in existing definitions. A still further interest attaches to their work in 
that they outline a scheme suggesting how it may he possible that the eucalypts 
have been evolved from the closely similar genus Angophora and subsequently 
varied into their present forms. Mr. Baker has separately published a beautifully 
illustrated work on the technology of the Hardwoods of Australia, in which the 
eucalypts claim chief space and attention. Mr. L. Rodway in his Tasmanian 
Flora and in the Government pamphlet Tasmanian Forestry has given us valuable 
information about the several species indigenous to his State, in respect both to 
their botanical characteristics and their uses as timber trees. 
DETERMINATION OF SPECIES. 
In assigning any Eucalyptus tree to a specific group the botanist has to con¬ 
sider the following tests of specific distinction:— 
(a) The form and aspect of the tree as a Whole. 
(b) The bark, with careful distinction between living and dead stages. 
(c) The foliage, including seedling, sapling, and adult forms. 
(d) The buds, flowers, and fruits, including study of the seeds. 
(e) The timber, especially in the heartwood or mature condition. 
(/) The oils and kinos. 
The ordinary student or forester cannot he expected to work out all these 
tests for himself; but it is well that even he should know in outline the process that 
must be followed to reach certainty in any of the more difficult determinations. 
{a) FORM AND ASPECT OF THE TREE AS A WHOLE. 
In studying trees we have to distinguish between what may be called the 
individual form and the group or specific form. No two trees, however nearly 
related, will be found upon close scrutiny to be exactly alike. Each tree, like 
each animal, has its own peculiar constitution and temperament, and differs from 
all others. The soil in which it grows and the presence or absence of other trees in 
contiguity may also modify it as a unit. This is individual form. But if several 
trees are very closely related, they will resemble each other in certain common 
features of structure and aspect. In other words, their kinship will he suggested 
by a manner of growth and colouring peculiar to them as a group. The tendency 
in a group or species may be towards a multi-stemmed canopy, towards a short 
stem heavily branched from near the ground, or towards a long clean stem with 
little top. it may he towards an erect habit of the branches or towards a spreading 
and drooping habit. Each group will also have a tendency to exhibit a peculiar 
colouring and aspect of both bark and foliage. This is group or specific form as 
distinguished from individual form. Looking at any tree as a whole the experi¬ 
enced botanist or forester will get an impression more or less certain as to the 
species to which it belongs; but to exclude all risk of error he will proceed to 
consider the other specific characters. 
ci. 
