PRESIDENT'S ADDRESS. XV. 



males occurring in the ten first generation families, though usually the band on 

 the hindwing above is quite absent ; it somewhat resembles fig. 801, more especially 

 on the forewing, and is not uncommon at Port Macquarie; fig. 6, is a, first genera- 

 tion female of the type of fig. 5. The second generation hybrids are shown in 

 figs. 7-12 and are all from the same family ; fig. 7, a male, is close to fig. 805 and 

 fig. 8, also a male, agrees with fig. 795; fig. 9 is a female agreeing fairly well 

 with fig. 803 and also approaches the typical morrisi; fig. 10 is a male agreeing 

 with fig. 809; fig. 11 is a female agreeing with fig. 3 of the first generation and 

 is somewhat like fig. 812; fig. 12 is a male very like fig. 811; fig. 8 is the male 

 parent of all the third generation hybrids I have reared. The third generation 

 hybrids are shown in figs. 13-15; fig. 13, a male, is almost identical with fig. 800; 

 fig. 14, a female, approaches fig. 798, but has the hindwing band much reduced; 

 fig. 15, a male, approaches fig. 811. In making a comparison between the hybrids 

 I have reared and specimens of joanna caught at Port Macquarie, it must be 

 remembered that the comparison between males is easier than between females, 

 for I have reared nearly an equal proportion of the sexes whilst, as is usual, 1 

 have only been able to catch about one female to every five males, even though I 

 searched for the former more thoroughly. I have therefore a much smaller num- 

 ber of females of Joanna with which to compare my hybrid females. 



It is not contended that I have been able to obtain amongst my hybrids a 

 specimen identical or even nearly so with every specimen of the 300 specimens of 

 Joanna obtained by myself at Port Macquarie or those caught there by Messrs. 

 Lyell and Wylde. The number of hybrids reared is only about one third of the 

 number of specimens of joanna available for comparison and by far the greater 

 number are of the first generation. It is improbable that at the present time an 

 equivalent of the first generation hybrid ever occurs. When the experiment is 

 continued beyond three generations a gTeater similarity with existing specimens will 

 no doubt be reached. The above comparison with a careful examination of the 

 coloured plates proves my contention that the race joanna at Port Macquarie is 

 a natural hybrid resulting from the crossing of the broad orange-banded southern 

 form with the narrow white-banded northern form. 



It has not been possible to give figmres of the parents of the families, for, 

 as they have to be kept in the cages sometimes as long as four days, they naturally 

 become worn and ragged. This happens especially with the females, as they are 

 left until I consider all their eggs are laid ; the males are killed as soon as I am 

 satisfied that pairing has taken place. 



I propose as soon as possible to continue these experiments to a much 

 greater number of generations and also to see what will be the results by pairing 

 somewhat similar specimens of joanna from Port Macquarie and also the results 

 from widely different specimens. 



The Relation op Tisiphone to the Physiogeapht 

 OP Eastern Australia. 



Those who have studied Australian physiography agree that the events of 

 the ultimate and penultimate chapters of the development of Eastern Australia 

 present the following sequence. At a period roughly dated as Pliocene, pene- 

 planation of this area was in an advanced stage; the shore stood farther east- 

 wards, trespassing upon what are now the Tasman and the Coral Seas, the 

 watershed was lower than at present and lay further westward, whilst the land 

 continued south to Tasmania and beyond and north to New Guinea. 



To this epoch of teirestrial stagnation there succeeded what Mr. E. C. 

 Andrews has called appropriately the "Kosciusko cycle." Then the coast re- 



