20 Evidences of a Glacial Epoch in Victoria 



after it the forms of life peculiar to it, and the different 

 climate which follows on its heels cuts off the laggards and 

 stragglers before they fall very far in the rear of the main 

 body. Now, according to Wallace, this process is going on 

 in Australia. He tells us that our tropic flora is wanting in 

 several important tropic families, which are, singularly 

 enough, to be found in our temperate regions. Such are the 

 Dilleniacece, Liliacece, Polygalece, and many others (Wal- 

 lace's Australia, 222). The presence of such tropic forms 

 in these temperate regions shows that not long since a tropic 

 climate reigned there, and that it has moved away equator- 

 ward faster than the vegetation could follow it. The tropic 

 regions to the north of them, and into which they have not 

 yet passed, is poor in vegetal life, because it has only recently 

 emerged from the sea, and the immigrants from the 

 south, and proper to it, have been slow in coming. 

 Again, such a submergence as we suppose accompanied 

 a glacial period would cut Australia into two parts at 

 least, an east and a west island ; and the marked 

 difference between the eastern and western floras accord 

 with such a severance. Out of four hundred and fifty 

 known species of acacia, melaluca, and eucalyptus, not a 

 single one is common to the two provinces. " The large 

 genera common to both sides of the continent are," says 

 Wallace, " wonderfully distinct'.' (Wallace's Australia, 46). 



Furthermore, as the retiring tide leaves behind it pools 

 which indicate levels recently attained to, so a retiring tem- 

 perature leaves in its wake its flotsam and jetsam to attest 

 its former presence in latitudes now behind it. As the tem- 

 perature of a locality rises, some of its flora and fauna may 

 remain, and yet save themselves from extinction by having 

 access to higher lands. Thus it is that the Antarctic genus 

 Drimys still lives far up on the lofty heights of New Guinea 

 (Wallace's Australia, 444) and of Borneo (ib., 353), after its 

 congeners have wandered southward some thousands of miles, 

 and that thirty-eight species of European plants are found 

 on the mountain peaks of Victoria wherever they rise over 

 5000 feet in altitude. 



Similarly, as the temperature falls, some plants secure, 

 themselves by retreating to sheltered spots, where they sur- 

 vive after their neighbours have either moved on or been 

 destroyed. We have such a relic of torrid times in Victoria 

 in the cabbage-palm, which is found in the warm, moist, and 

 well-sheltered gullies of Gippsland, although outside of these 



