PESIDENTIAL ADDRESS. 31 
species are, however, easily susceptible to the effect of 
constructive poisons is indicated by the destructive effects 
of Loranthus when this parasite takes possession. A few 
years ago some fine trees of “‘ Blackbutt’”’ H. pilularis were 
growing in the neighbourhood of the Marrickville Railway 
Station. They became badly infected by the ‘‘ Mistletoe ”’ 
Loranthus sp., and after a time first one and then another 
died, until all were eventually destroyed. This result is, 
in certain localities, not an uncommon occurrence with the 
Kucalypts. 
It is, perhaps, largely due to the composition of the soil 
upon which these little ash-giving species choose to grow, 
and the comparatively small amount of the necessary 
mineral food available in like situations, that these par- 
ticular Eucalypts have acquired the power of almost 
dispensing with the necessity of storing mineral material 
in the trunk of the tree, perhaps with the object of not 
depriving the leaf portion of the required mineral food 
supply. It can be readily calculated how large an amount 
of mineral matter would be stowed away in the trunks of 
these enormous Hucalyptus trees, if the percentage was as 
large as that found in the timbers of the smaller trees of 
some other groups. The giant trees of HE. regnans growing 
in the Gippsland Ranges of Victoria are cases in point. 
These trees are sometimes over 70 feet in circumference, 
and nearly 400 feet in height. A sample of the timber 
from a smaller tree of this species from near Warburton in 
Victoria gave only 0°054 per cent. of ash, calculated on the 
anhydrous wood, so that a ton of this wood, when freed 
from moisture, only contained one pound three ounces of 
mineral substances. This result is quite in agreement with 
the ash contents of the timbers of other species belonging 
to this and closely associated groups, so that it may be 
assumed, from these data, that the largest trees of this 
species of Kucalyptus only store up mineral matter in their 
