8 PRESIDENT S ADDRESS. 



Australia, to be older than any other part of the continent, com- 

 prising as they do the so-called Larapintine limestone of Silurian 

 formation. The oldest known rocks on our own mountains con- 

 sist of slates and limestones, also of Silurian age. 



In Mesozoic times, the Australian flora consisted mainly of 

 Eiliees, Lycopodiacce, Equisetacece, Coniferce, and Cycadaccay, 

 but, in Tertiary times, these were almost superseded by a very 

 different flora, including among other trees the Oak (Quercus), 

 Beech and Cinnamon. The Equisetacece have long since disap- 

 peared ; the Lycopoilincfff, which formerly attained the height of 

 50 feet, have dwindled down to 12 inches; the Coniferce are repre- 

 sented by Araucaria, Podocar/nis, Dammara, and a few other 

 genera, most of which are only found in the north ; various 

 Cryptogams still flourish in such places as our now arid climate 

 will permit, but the Cycads which flourished to an enormous 

 extent in Oolitic times in Europe, and have now quite disappeared 

 from that region, have managed, in the shape of Zamias, to sur- 

 vive all misfortunes, and still grow profusely in Australia, and 

 are looked upon by botanists as examples of living fossils. 



The old flora, except in some instances, the survival of which 

 is difficult to account for, perished, but, when Australia, in the 

 Tertiary period, finally arose from her watery bed, it was suc- 

 ceeded, in the later part of that period, by a strange flora, differ- 

 ing almost entirely from the floras of every other part of the 

 world. In particular the Eucalyptus and other giant species of 

 Myrtacece then began, as they do now, to clothe the surface, 

 almost to the exclusion of all other orders, and, having spread 

 uninterruptedly (probably from west to east) have gone on, for 

 vast periods, producing from time to time new varieties, which 

 have ultimately become species, as they advanced from one side of 

 the continent to the other, and these species have been continually 

 inter-fertilizing, and producing such a tangle as makes a definite 

 and reliable classification by botanists almost an impossibility. 



It must be evident that these processes occupied a vast space of 

 time, and that they could not have been interrupted, during their 

 whole operation, by any general submergence of the surface, for 



