On the pliysiograpby of Northeastern Australia. 17 



that tbe graduai filling up of the lake beds with drift, and the dee- 

 pening of the Channel of the Condamine River which drains the 

 country, conjoined probably with a graduai decrease in the annual 

 rainfall, hâve combined to change a swampy country covered with 

 coarse reedy végétation into open downs and plains, producing short 

 grasses totally inadéquate for the support of animais with the heavy 

 frames and peculiar teeth which characterised the majority of the 

 ancient occupants of the district." 



„There is no trace either in the Darling Downs or any other 

 part of Queensland of any violent convulsion of nature which would 

 be adéquate to cause the total destruction of the Diprotodon and co-oc- 

 cupants of the country, and it seems most probable that their ex 

 tinction resulted from a graduai change of climate, and more effectuai 

 drainage through the deepening of the Channels of the watercourses 

 — aided, perhaps, by some slight changes of level." 



Such conditions as put down hère were completely in accor- 

 dance with the character of the tertiary flora. It seems unnecessary 

 to deal with this point at a greater length, the proofs of a very 

 convincing character having been collected by Mr. Deane and Mr. 

 Andrews in their respective papers. 



1 may only quote the following passage from Mr. Deane's a ) 

 study „ . . . the climate having been then moister it is probable that 

 there was formerîy a much larger area over which the two eastern 

 éléments (Torresian or Papuan or Bassian), and especially the Tor- 

 resian, predominated and the sway of the western element was re 

 stricted. When the centre of Australia was largely lacustrine, and hot 

 wind and drought were less of a féal ure in the climate, the Torresian 

 element of the Flora might readilly be supposed to extend as far as 

 this, and there would at that time hâve existed a luxuriant végéta- 

 tion, one of the last relies of which is the Central Australian Palm 

 „Li vi s ton a Mariae". 



From Mr. Andrews 2 ) paper I may only quote the following 

 words concerning the fossil flora of the so called deep „leads" of 

 Upper Pliocène time, which points to a „mild and fairly uniform cli- 

 mate extending right from Hobart to north Queensland" (Page 453.) 



1 ) Observations on the Tertiary Flora of Australia, with special reference 

 to Ettinghansen's Theory of the Tertiary Cosmopolitan Flora. Proč. Lim. Soc. N. 

 S. Wales 1900. Vol. XXV. Page 466. 



2 ) Geographica! Unity of Australia. 



