XVI. president's address. 



treated westward, the coastal mountain range rose higher, Torres and Bass 

 Straits opened. Synchronous with these events occurred a glacial phase which 

 has written its story in moraines across the face of Kosciusko. Movement of 

 the coast range re-organised the rivea- system and exposed different rocks on the 

 surface. Changes in climate played on each organism and the vegetation, as 

 Mr. R. H. Cambag-e has described so clearly in tbie case of the Eucalypts, re- 

 sponded to the change of environment. Specific differentiation in both fauna 

 and flora then proceeded rapidly. 



The palaeontological record shows so far no fossil butterflies earlier than 

 the Tertiary, but in the Oligocene of both Europe and North America we find 

 "ossils of even the more developed gToups and, included amongst these, several 

 fossil Satyrids. Present day Satyrids are of world-wide distribution and there 

 is every possibility that as early as the Miocene they bad a similar distribution 

 and that the ancestral forms of our present Satyrids were then in Australia. 



It is reasonable to suppose that, before the great uplifting movement at the 

 end of the Pliocene, the ancestor of Tisiphone was present in Eastern Australia. 

 I consider that first of all the genus became restricted to the higher elevations 

 where moisture was more abundant. At the low-lying portion of the main 

 divide known as the Cassilis Gap, the conditions became unsuited for its existence 

 and it disappeared. This barrier then produced a discontinuous distribution and 

 allowed the ancestral Tisiphone to develop independently to the north and to the 

 south, gi-adually producing what we now know as broad orange banded forms 

 in the south and narrow white banded foi-ms in the north. The southern form 

 now occurs almost up to the southern end of the Cassilis Gap and, though no 

 form has been taken near the northern end of the Gap, the white banded form 

 occurs at the southern -end of the Mt. Royal Range almost in the same latitude. 

 As time progressed the two forms were able to reach the coast, the southern 

 probably first, and finding suitable conditions moved northward and southward, 

 meeting in the small area of Port Macquarie and thus were able, in fairly recent 

 times, to reunite and fonn the vei-y complex race Joanna there. Tasmania, though 

 possessing the foodplant, does not possess any Tisiphone, which may possibly 

 have died out or was not in a position to pass along the land connection at what 

 is now Bass Straits. This would point to Tisiphone belonging rather to the 

 earlier of the newer Papuan invasions from the north than to the older Satyrid 

 fauna oeeumng in South-eastern Australia and now represented by such genera 

 as Heteronympha and Xenica. 



Though these experiments were started with the definite object of proving 

 Tisiphone Joanna a natural hybrid, which I claim to have shown, many other in- 

 teresting problems have presented themselves, but sufficient time has not been 

 available for their complete study and so they must be left to some future oc- 

 casion. The great question of heredity stands first, but I have not had suf- 

 ficient time to make the thorough examination necessary, nor do I consider 

 that the number of specimens obtained, particularly in the second and third 

 generations, is lenough to enable sound conclusions to be drawn. I propose, there- 

 fore, with the increased facilities at my disposal and the experience I have 

 already obtained, to repeat the experiment of obtaining t«n families of hybrids 

 from abeona and m.orrisi and aim at getting a much larger number of specimens 

 of the second and third generations and even carrying on the experiments to 

 further generations. Though the coastal strip from Twofold Bay to Caloundra 

 has been carefully and thoroughly collected — the only point of investigation being 

 the nature and extent of the ba,rrier separating morrisi and rawnsleyi — the Main 

 Divide has been imperfectly worked as will be seen from the map (PI. i.) ; the 



