EUCALYPTUS TREES. 67 
precise quantity’‘of tannic substance to be obtained 
from saplings and foliage of various Eucalypts, acacise 
and casuarine remains yet unascertained ; but it is 
likely large enough to base on their yield of tannic 
acid special forest industries. 
For belts of shelter-plantations, again, no country 
in the warm temperate or subtropic zone could choose 
trees of easier growth, greater resistance, rapidity of 
increment, early and copious seeding, contentedness 
with poor soil, and yet valuable wood for various pur- 
poses, than some of the Australian acaciz and casua- 
rine. They exceed much in quickness of growth the 
coast shelter-pines of South Europe, Pinus haleppen- 
sis and Pinus pinaster, but are not all equally lasting. 
The trade in seeds of this kind is also not unimpor- 
tant, and the sources of it are, at least partly, in our 
sylvan land. 
Still another forest industry might be viewed as 
especially Australian, namely, the supply of Fern-trees 
for commercial exportation. Though about one hun- 
dred and fifty kinds of Fern-trees are now known, 
they are mostly children of tropical or subtropical 
countries, and these, again, nearly all restricted to the 
humid jungles or the shady valleys meandered by for- 
est brooks. Very few species of these noble plants 
extend to a zone so cool as that of Victoria, Tasma- 
nia, and New Zealand. Again, among this very lim- 
ited number, the stout and large Dicksonia antartica 
is not only one of the tallest of all the Fern-trees of 
the globe, but certainly also the most hardy, and the 
one which best of all endures a transit through great 
distances. Indeed, a fresh, frondless stem, even if 
weighing nearly half a ton, requires only to be placed, 
