CLASSIFICATION OF THE EUCALYPTS. 545 
foliage of the taller mallees may be largely incidental to over- 
crowding, though it would seem to be an inherited character as it 
is fairly pronounced in them when they are distantly separated 
from one another. 
TIMBER. 
Two extremes in the property of timber occur, (1) the fissile or 
readily-splitting timber as that of Z. globulus, EL. amygdalina, 
and other so-called stringybarks ; (2) the short-fibred timber as 
that of Z. rostrata. Moreover, the duramen is fairly constant in 
colour for each species, varying from mahogany-red to yellow and 
white, and though the general character of the timber is invariable 
for each species, yet the quality of it varies according to climate 
and soil, so that the forester’s appreciation of specific differences 
cannot safely be availed of for the systematic arrangement of the 
Eucalypts. Thus, for example, the wood of Z. rostrata growing 
on river-ways is of very inferior quality as a timber, and is even 
rejected as firewood when other sources of supply are obtainable ; 
but as the tree ascends the slopes of high elevations, up to about 
2,000 feet in South Australia, the timber improves in quality, and 
at its best ranks as highly valuable. 
BARK. 
The differences in the nature of the outer cortical layers led 
Baron von Mueller (Journ. Lin. Soc., III, 1858), to arrange the 
species into the following groups :— 
1. Leiophloie, or smooth-barked trees, as £. rostrata, 
£. leucoxylon, &c., and the majority of mallees. 
bo 
. Hemiphloie, or half-barked trees ; bark of lower trunk 
persistent, of upper part and branches deciduous, as 
EL. hemiphloia, E. oleosa, 
. Lhytiphloie, with wrinkled persistent bark, as LZ. robusta, 
£. corymbosa, EL. amygdalina, E. odorata. 
oo 
ia 
Pachyphloice, with persistent fibrous bark, as #. gigantea, 
£. calophylla, E. obliqua, and other stringy-barks. 
OO 
. Schizophloie, with persistent deeply-furrowed bark, as: 
£. crebra. 
6. Lepidophloiw, with persistent bark on the trunk only, and: 
forming scaly separate pieces, as Z. tessellaris. 
This cortical system has its utility; but there are several species. 
which exhibit inconstant characters, as for example, /. hemiphloia 
in its ordinary state is typical of section 2, but in the high uplands. 
of the Mount Torrens district of South Australia it assumes the 
characteristics of section 4 and is locally known as “ Bastard 
Stringy-bark.” Mr. Maiden, P.L.S., N.S.W., 4, p. 1278, 1890, 
2 -M 
