ON THE PINES OF AUSTRALIA. 181 
2. The ‘‘White Pine’’ of New South Wales is Callitris 
glauca, R.Br., the old name C. robusta, R.Br. being retained 
for the West Australian species, with its large fruits, and 
other specific differences. The former has been found to 
retain a comparative constancy of botanical and chemical 
characters throughout its geographical range. The sec- 
tions of the leaves show features distinctive from those of 
other Pines. 
3. The microscopic structure of the timber of C. glawea is 
very interesting, and appears to demonstrate a geological 
connection with its progenitors. 
4, The essential oil from the leaves of this species of Calli- 
tris is practically always the same, no matter where 
grown. The oilfrom C. glauca is comparable with the best 
‘Pine Needle Oils’”’ of commerce. 
d). The rotation of the terpenes of the oil from the leaves 
of most species of Callitris, is in the opposite direction to 
that obtained from the fruits, even if collected from the 
Same tree. 
6. The oil obtained by steam distillation from the timber 
of this Callitris, contains the sesquiterpene alcohol guaiol. 
in some quantity, the sesquiterpene is also present. 
The characteristic odour of Callitris timber is due to a 
phenol. This has distinctive colour reactions and is 
evidently new. The name Callitrol is proposed for it. 
EXPLANATION OF PLATES. 
Fig. 1.—Transverse section, showing the earliest stage of con- 
crescence in the leaf, and where the three divisions are beginning 
to individualise. x 80. 
Figs. 2, 3.—These show the concrescent portions more distinctly, 
also the fuller development of the ventral surfaces, and the cuticle 
protuberances on them. The hypodermic cells are distinguishable 
in the lower part of Fig. 3. The leaf structure explained in the 
