30 H. G. SMITH. 
quantity in the ashes of species belonging to some others, 
particularly those of the typical ‘‘Boxes,’’ (See Table II). 
Phosphorus is always present, although in certain species 
or groups it isin comparatively small amount, while in the 
ashes of all the ‘‘Stringybarks’’ and allied groups alumina 
was always detected, as well as a small amount of iron. 
Potassium was, of course, always present, although very 
small in amount in some species, as well as varying quan- 
tities of sulphur, and in some cases chlorine and sodium. 
The alkalis are more pronounced in the ashes of those 
species in which calcium is less abundant, and the largest 
percentages of phosphorus are found there also. 
A considerable number of Hucalypts, particularly those 
belonging to the groups in which calcium is a pronounced 
constituent, construct oxalic acid as one of the products of 
metabolism. In some species the oxalic acid is often pro- 
duced in such abundance that in some cases as much as 
one-sixth of the air dried bark consists eventually of calcium 
oxalate. These species, however, are usually of small size, | 
often occurring in the shrubby or ‘‘Mallee”’ form. It is 
hardly to be supposed that such Hucalypts would live long 
enough to enable them to grow into very large trees, so 
that the largest EKucalypts of Australia can hardly belong 
to groups the members of which are subjected to such 
adverse chemical influences. The gigantic Eucalyptus 
trees of this continent, as, for instance, those belonging to 
such species as H. regnans, EH. pilularis, H. Delegatensis, 
EK. obliqua, etc., only use calcium in comparatively small 
quantities, while magnesium is an important mineral con- - 
stituent in these trees. Species belonging to such groups 
do not, under ordinary circumstances, form oxalic acid in 
excess, nor other poisonous constituent, so that it is not 
unreasonable to assume, that under the most favourable 
conditions these EKucalypts could continue to construct 
their woody tissue for thousands of years. That these 
