MOUNTAINS AND THEIR EFFECT ON NATIVE VEGETATION. 275 
vegetation is kept back to the eastward and the western 
or inland flora comes through on to the eastern watershed. 
The Kilmore Geocol in Victoria is situated so far towards 
the cooler southern latitudes that its elevation, about 1,200 
feet, is sufficient to allow the colder-loving type of plants 
suchas Eucalyptus amygdalina (Messmate or Peppermint), 
E. dives (Peppermint), and H. viminalis (Manna Gum) to 
continue in and across the depression, and as the divide 
runs east and west at this point, it is fully exposed to the 
cold from the south, and there is consequently no’consider- 
able invasion of either inland or coastal plants to the 
opposite side. 
The Omeo Geocol is situated on an angle of the Main 
Divide where, after coming from the west, it swings round 
to the northward into New South Wales, and being about 
3,000 feet high, has a climate sufficiently cool for the growth 
of such mountain species as Eucalyptus coriacea (Snow 
Gum), EH. stellulata (Sallow or Sally), E.camphora (a Swamp 
Gum), and E. rubida (a White Gum). It forms a plateau 
about ten miles wide across the main axis of the mountain 
from which the waters fall steeply into the Mitta Mitta 
on the north and the Tambo River on the south. Within 
forty miles on either side of the Omeo Geocol the Main 
Divide rises to elevations of 5,000 to 6,000 feet. This 
geocol, though a distinct mountain gap, is sufficiently high 
to form a natural barrier between two floras, but yet such 
species as Eucalyptus albens (White Box) and E. macror- 
rhyncha (Red Stringybark) which prefer a dry to a moist 
atmosphere, and are not found on the summit of the range 
in the geocol, have managed to cross this narrow barrier 
from north to south, and occur below the level of the snow- 
falls in the warm valley of the Tambo. The presence of 
these two species on both sides of the Main Divide without 
their being able to exist on the summit, is of interest, and 
