Primitive Australia. g 



that Australia was a great continent, extending to about three 

 million square miles, so that it was more than three-fourths the 

 size of Europe. It was remarkable for the varied conditions found 

 in it ; the north was tropical, the centre was desert, and at certain 

 seasons was intensely hot, while at others the nights were 

 extremely cold ; while the south was very variable. Naturally the 

 plants and animals differed in these regions, as did also the habits 

 of the black fellows. The plants of Australia were of great inte- 

 rest. Many of the types were similar to those that existed in 

 Europe in tertiary times, and it seemed probable that in Australia 

 there were survivors of a formerly widespread flora, But while old 

 types had been preserved they had not remained unchanged, but 

 had become adapted to the varied conditions that prevailed in 

 Australia. The result was that there was an enormous number of 

 peculiar species that were found nowhere else in the world. 

 Another notable feature of Australian vegetation was its uniformity 

 over great areas ; the dense uiallee scrub occurred in patches of 

 hundreds, and even thousands, of square miles, and heath, 

 spinifex, and the gum tree were all curiously dominant over vast 

 areas. The animals of Australia were markedly primitive. 

 Australia appeared to have been cut off from the continent of 

 Asia since mesozoic times, with the result that the fiercer and 

 more intelligent groups of mammals had never got a footing in it. 

 The old-fashioned marsupials which abounded throughout the 

 world in mesozoic times were still dominant, but they showed 

 specialization of many kinds ; some were herbivorous, others 

 carnivorous, some burrowed, while others climbed trees. The 

 animals that attracted him most were Ceratodus, the lung-fish, 

 and Platypus, which, though a mammal, laid eggs. Ceratodus 

 was known as a fossil long before it was discovered in the Mary 

 and Burnett Rivers in Queensland. It and its near relatives 

 flourished in early mesozoic times ; but the group Dipnoi had all 

 but disappeared, and at present they had only some species in 

 Australia, one in Africa, and one in South America. In many 

 ways Ceratodus suggested amphibians, and it was possible that 



