SUNKLANDS OF PORT PHILLIP BAY AND BASS STRAIT 115 
Isthmus. It would seem, therefore, that the King Island Isthmus 
was a main route for migration. 
It is axiomatic that, if an herbivorous fauna passes over a land 
bridge, its passage must have been preceded by a migration of the 
flora. The Yolandean land surface was covered with an old and 
well established flora, but on the eustatic land bridges a new flora 
had to come into being. Conditions affecting the birth of this 
new flora were regulated by the nature of the land surface and 
the climate. 
The Ranges of the Pleistocene Climates in South-East Australia. After Griffith Taylor (1919). 
Eegarding the latter, the period was one of changing climate : 
there were successive cool moist and cold wet periods, during 
which glacial conditions existed in the Tasmanian highlands. 
“Ecologically, Tasmania is connected,” states Patton (1930), 
“with the three heavy rainfall areas (of Victoria), South Gipps- 
land, Otway and the Warburton-Healesville area,” the first two 
bordering on Bass Strait ; elsewhere he states that the vegetation 
of the two areas is similar, and passes down into Tasmania. They 
carry a close-canopied rain forest consisting of several strata. 
The rainfall of the glacial stages was certainly greater than it is 
now, and the Bassian flora grew on a well-watered land surface. 
He also points out that these heavy rainfall areas in Victoria are 
the meeting places of Antarctic and Malayan elements, the first 
by Nothofagus and Lomatia Fraseri occurring in Tasmania and 
