During Post-Miocene Times. 25 



times has been used to prove the impossibility of a glacial 

 epoch having occurred in Australia. We must ; therefore, 

 devote some consideration to the arguments and evidence of 

 those who hold views which differ from those set forth in 

 this paper. 



III. 



The Rev. Julian Woods, in the year 1867, contributed to 

 this Society a paper designed to prove that there had never 

 been a glacial period in Australia within tertiary times. 



He based his conclusions upon the following grounds : — 

 Firstly, because our early tertiary fossils have a tropic facies ; 

 secondly, because our miocene shells are identical with 

 species . now living under the equator ; thirdly, because 

 South Australian pliocene shells are also identical with 

 tropical species ; fourthly, because a Tasmanian pliocene 

 formation has been found with a fossil palm in it ; fifthly, 

 because the quaternary shells of Western Australia present 

 a tropic aspect. 



Upon the strength of such evidence he decides that Aus- 

 tralia has not experienced a glacial epoch within tertiary 

 times, but that, on the contrary, the climate was very warm 

 in early tertiary times, and has been cooling down ever 

 since. 



In criticising this evidence we have a great advantage 

 over the rev. gentleman, because we to-day understand the 

 nature of glacial periods much better than we did fifteen or 

 twenty years ago, when he wrote. 



In consequence of the greater acquaintance with the sub- 

 ject which geologists now have, we know that each glacial 

 epoch contained within it a set of warm periods as well as 

 of cold ones, and that the tropic forms which he has relied 

 upon would flourish during any one of them. These hot 

 and cold periods were complimentary to each other in a 

 glacial epoch, and their occurrence, as testified to by these 

 shells, is strongly confirmatory of the occurrence of such an 

 epoch. 



If we take the evidence and examine it separately, we find 

 that it confirms this view ; for instance, Woods mentions the 

 fossil shell Fusus colossus, found in Western Australia, and 

 points out that it is now represented only by species confined 

 to the tropics. Therefore he tells us that colony cannot have 

 experienced a cold period. I contend that the evidence 

 proves no more than this, that a warm climate prevailed 



