546 PROCEEDINGS OF SECTION D. 
writes: “ I have seen bark of Z. ste//ulata (which Mueller includes 
in section 5), which cannot be distinguished from what are known 
as ironbarks.” 
EXUDATIONS. 
Mr. J. H. Maiden, Proc. Lin. Soc., New South Wales, 1890, p. 
605, as the result of extensive and repeated investigations, has 
shown that the A%nos, or astringent exudations, may be readily 
grouped into three sections according to their behaviour with 
water and with alcohol ; and has proved, further, that a kino of 
one species invariably belongs to one group. He would employ 
this chemical system of grouping the Eucalypts as supplementary 
to, or a check upon, the anthereal (or other) system. His classi- 
fication of the Avnos is as follows :— 
(1.) The Ruby Group, which consists of ruby-coloured Ainos, 
the members of which are soluble either in cold water or 
in cold spirit. To this group belong Z£. obliqua and 
other species having kidney-shaped anthers. 
(2.) The Gummy Group, whose members are soluble in cold 
water, but very imperfectly in spirit, owing to the gum 
they contain, such as &. siderophloia and some other 
ironbarks. 
(3.) The Turbid Group, whose members are soluble in hot 
water or in hot alcohol, but the solutions become turbid 
on cooling; all the members of this group contain 
catechin, such as #. rostrata, £. leucoxylon, Xe. 
FOLIAGE 
Don, 1832, classified the then described Eucalypts into two 
primary sections according to the alternate or opposite position of 
the leaves; but it was pointed out by Bentham, Fl. Aust., 111, 
p. 187, 1866, that a great majority of the species are now known 
to have on the young sapling, or even on adventitious barren 
branches of older trees, opposite leaves. The leaves of the young 
plants of all the species with which I am acquainted are opposite, 
horizontal, often sessile, bluish, and more or less oval, eventually 
in the great majority of species becoming alternate, lanceolate, 
vertical, stalked, and green. This feature has been largely illus- 
trated by Baron von Mueller in “ Hucalyptographia,” Decade 
9, and by Sir John Lubbock in his “Seedling Plants.” The 
opposite-leaved condition would appear to be the primitive one, 
and in a few species, such as Z. gamophylla, persists throughout 
life. 
Little value can be placed on leaf-shape, as in general there is 
great similarity among different species, and often great diversity 
