132 ■ THE GREAT BARRIER REEF. 



1889, to the effect that the arguments in favour of Mr. Darwin's hypothesis "nearly all hinge on 

 assumptions that cannot be proved." 



The Great Barrier Reef of Australia not having, so far, been cited as a direct witness, one 

 way or the other, in the difference between Dr. Murray and Mr. Darwin, such evidence as it 

 can be made to disclose is invested with special interest. The most extensive reef-formation 

 of the Barrier class throughout the universe, it occupies a crucial position with relation to 

 the controversy — that, in fact, let it be premised, of the last line of defence, or inmost 

 citadel of the Darwinian subsidence theory ; whence, should the case for the defendants be 

 made good, the enemies' camp can be invaded and despoiled. 



And now to our guns ! Attention has been already drawn, pp. 1 10 and 1 1 1, to the fact that 

 all of the few big breaches in the Barrier's outer rampart — to wit, the Trinity Opening, Flinders' 

 Passage, and Capricorn and Curtis Channels — are opposite large estuaries, though at the 

 present time too remote from them (thirty to sixty or eight}' miles) to be influenced by their 

 streams. Although seemingly an unprovable assumption, it is maintained that these breaches 

 in the outer Barrier wall were once in close proximity to the mouths of the rivers, and, in fact, 

 owe their origin to the restraining influence of fresh waters on the coral-growths. To substan- 

 tiate this assumption we resort to a magazine of ammunition that, whilst near at hand, has 

 hitherto been unbroached. What, it may be asked, is the logical significance of the following 

 facts ? In the equatorial island of New Guinea there are birds and mammals identical with, or 

 most nearly related to, forms living on the North Australian (Queensland) mainland. The 

 flightless Cassowary, Casuarins, among birds, is one of the most notable of these ; but it 

 is in the mammalian list that we find the most substantial evidence. The Spotted Cuscus, 

 Cttscus maculata, of New Guinea and that of North Queensland are specifically identical ; and 

 the same may be said of the species of the so-called Native Cats, Dasyurus, and of the Ring- 

 tailed Opossums, Pseudochirus. The interesting group of Tree Kangaroos, genus Dendrolagus, 

 hitherto supposed to be confined to New Guinea, has recently been found to possess a 

 Queensland species, D. Liimholtzi, while an ordinary Grass Kangaroo, genus Macropus, nearly 

 allied to M. major, most abundantly found on the Australian Continent, is an inhabitant 

 of New Guinea also. Several species of the Flying Opossums, genus Petaurus, and allied 

 types, are represented both in New Guinea and throughout Australia ; and the same formula 

 of distribution applies to the slender-limbed Bandicoots, of the genus Perameles. The 

 essentially Australian group of the Monotremata, including the Echidna and the Platypus, 

 its only living members, is represented in New Guinea by a species originally referred to 

 the first-named of these genera, but on account of certain anatomical differences associated 

 with the separate generic title of Proechidna.* 



* Readers wishing to pursue this most interesting subject are referred to that very admirable handbook, 

 "Mammalia, Living and Extinct," by Professor (now Sir WilHam) Flower. F.R.S., and Mr. R. Lydekker. 



