The South Australian Naturalist. 
103 
the rain would reach tJie main channel much more slowly, and 
thus allow the ruinoft to extend over a longer period. Forests, 
then, ensure a regular flow of good water throughout the year, 
pid this water is generally clear and pure. This is of economic 
importance, as there is not the same need for water storage 
when the supply is permanent or regular. 
Then the influence on climate or rainfall is an important 
factor to be considered. Forests act as a cooling and condens- 
ing agent to the upper atmosphere, bringing about the pre- 
cipitation which would be impossible or unlikely with a barren 
landscape. The shade and shelter given by trees is for the 
benefit of man and his animals. Other points, such as the 
incomparable beauty of forest, with its association of bird, 
animal, and floral life, could l>e dealt with to show the value 
of forest growth, but I wish to mention some of our timbers 
Avhieh are of commercial value. 
The classificatio]! of the Eucalypts (1 will only deal with 
this^ genus, as it is practically our only timber-producing 
family) by means of their barks, as described by Mr. Maiden 
in his work, “Critical Revision of the Genus Eucalyptus^’ Part 
51, 1922, is as follows : — 
1. LEiOPIILOlAE (smootli barks or gums, oiiter layers 
shedding). 
2. HEMiPHLOlAE (half barks, ])ei’sistent and wrinkled 
on trunk). 
3. RHYTTPHLOIAE (rough barks). 
4. PACHYPIILOIAE (stringybarks, fibrous). 
5. SCHIZOPHLOIAE (ironbarks, deeply furrowed). 
6. LEPJDOPHLOIAE (barks friable an,d lamellar oi* 
scaly). 
Tn this classificatio]] our timber trees are represented by 
the following species: — 
I. LEIOPHLOIAE. Smooth barks or Gums. 
^ Trees more or less erect in liabit but not shaft-like: pale 
timbers. 
1. Eucalyptus leucoxylon F.v.M. “Yellow gum” (ime- 
viously called “Blue gaun”). This species grows to a fair- 
sized timber tree ajul is found in association with the red gum 
(E. rostrata), although it does not grow in such damj) situa- 
tions. It is a good tree for bees. Its flowers are large and o-ive 
a good sujiply of excellent nectar. 
2. E, rubida I3eanc and Maiden. ^^Candlebark. ” It is 
chiefly in the dam]) gullies that this tree is found and its 
distribution is wide in the hills within the 30-iiich rainfall but 
its numbers are very small. This is the most beautiful gum of 
