582 TRANSACTIONS OF SECTION K. 
critical revision, pointing out that no line of study which promised to throw 
light upon the genus had been neglected. He emphasised the point that a 
species must be judged as a whole, and illustrated this by analogies from the 
science of history, from literary criticism, and from industrial legislation, 
pointing out in proportion as a botanist grasps all the facts concerning a 
species, he becomes a broader-minded man. Although endless fun can be poked 
at the illogical positions in which we sometimes find ourselves by our conception 
of species, it is idle to attempt to abandon them, for plants will be labelled 
species on the evidence of our senses to the end of time. 
The writer concluded with a reference to the services of the great European 
herbaria in naming and preserving the types of Australian species at a time 
when there were no means of preserving such types in Australia herself, and 
entered a plea that as a recrudescence of botanical expeditions to Australia has 
now set in, our colleagues in Europe and America should see that specimens 
of their types are made available in some parts of this continent. 
2. The Correlation between the Specific Characters of the Tasmanian 
and Australian Eucalypts. By R. T. Baker, F.L.S., and H. G. 
SmitH, F.C.S. 
In this paper the authors brought under review the results of their recent 
research on Tasmanian Eucalypts, comparing them with their own earlier work 
on the Eucalypts of the mainland, supplemented by more recent data. The 
ground covered by these investigations, now extending over a period of a quarter 
of a century, embraces almost the whole geographical range of the genus—an area 
of the earth’s surface of about 3,000,000 square miles. Such an area includes a 
diversity of soils, climates, altitudes, &c., and naturally one looks for and finds 
a great variety of species, but it is found at the same time that a relative con- 
stancy of specific botanical features and chemical constituents characterises the 
whole genus. 
Comparisons, as well as contrasts, were made between the morphological and 
chemical features of the trees found at the sea-level and right up to the highest 
altitudes at which the correlated species occur both in Australia and Tasmania. 
Most interesting results have been the outcome of this work, and a theory is 
now advanced of the geological age of the Tasmanian trees in comparison with 
those of the mainland. It is also attempted to show that in the Tasmanian 
Eucalypts we have the more recently evolved of the whole genus. 
3. Notes on the Evolution of the Genus Eucalyptus. 
By R. H. Campaas, F.L.S. 
A feature of the genus Eucalyptus is its wonderful adaptability to environ- 
ment, and a brief sketch will show some of the changes it has undergone. 
We have fossil evidence of its existence in Australia since late Eocene or 
early Miocene, at which time our present mountain system had not developed, 
and the climate was a mild to warm one. Eastern Australia was then fairly 
level, and in early Eocene was largely composed of siliceous soils, much of the 
silica being in a free state, rendering the soils sandy. Subsequent lava flows 
and deposits of volcanic tuffs yielded a more basic soil, and the final uplift, 
parallel to the east coast, towards the close of the Tertiary, produced elevations 
which have a cold climate. 
Apparently the early Eucalyptus flourished in a sandy soil with a warm 
climate in Northern Australia. The bark was scaly to rough, the leaves 
opposite, sessile, horizontal and generally cordate, and often covered with 
stellate hairs or coated with caoutchouc. The leaves had a transverse vena- 
tion, the numerous lateral veins forming an angle of about 65 degrees with 
the midrib. The flowers were large as compared generally with those of the 
genus at the present day, and possessed anthers which opened longitudinally 
in parallel slits. The fruits were generally larger than those of the more recent 
species to-day, and the chief constituent of the essential oils contained in the 
