ix 



As yet no evidence of geological catastrophe or climatal change has been adduced to 

 account for the disappearance of Macropus Titan and the survival of Macropus major. 

 The latter is not a degenerate descendant of the larger extinct Kangaroo*. In the 

 section "on the extinct species of Wombat resembling the existing ones in size" 

 (p. 315), the number of such extinct forms is greater than that of "the extinct species 

 exceeding the existing ones in size " (p. 339). Indeed the most diminutive of known 

 Wombats is, geologically, as old in time as the most gigantic. But all the kinds that 

 did exceed the biggest known living Wombats have, somehow, disappeared ; so also 

 with the Kangaroos, and with their carnivorous marsupial enemies. 



To a race of man depending for subsistence on the chase, the largest and most con- 

 spicuous kinds of wild beasts first fall a prey. The smaller kinds, with swifter powers 

 of locomotion, more frequently escape and more easily conceal themselves. The limbs 

 of JJiprotodon and Nototherium suggest a slower, heavier mode of progression than 

 those of the Procoptodonts. The proportions, especially of the hind limbs, of the 

 latter extinct Macropodidce show an inferior power of saltatory course than is possessed 

 by the existing forms. The gigantic Kangaroos more nearly akin in limb-structures to 

 the smaller living kinds would be more formidable in defensive struggles, but less 

 favoured for retreat. 



As the elephant succumbs to the spears and pitfalls of the negro hunters, the minor 

 bulk of the Diprotodon is not likely to have availed it against the combined assaults 

 of a tribe of Australioid wielders of clubs and throwing-sticks. 



True it is that, as yet, no evidence of ancestry of the existing aborigines has been 

 detected in the caves and breccias yielding fossil remains of their hypothetic prey, 

 unless Ave assume the Dingo to have followed the Papuans in their immigration. But 

 the exploration of ossiferous caves has hitherto been limited to those originally dis- 

 covered by Sir Thomas Mitchell. And whilst I write, an announcement has reached 

 me of the discovery of others, sixty miles from Bathurst, in the limestone district 

 midway between Cowra and Canowindra, also in limestone ranges near the stanniferous 

 granites of Northern Queensland, which caves, if explored with due care, patience, and 

 skill, may bring to light some indications of the prehistoric men of Australia, as well 

 as largely supplement the partial restoration of extinct Marsupials in the following 

 pages. 



At present the evidence is negative; and its value must be estimated by the known 

 imperishable parts of the tools or weapons of the existing aborigines, which may bear 

 testimony to them in the absence of their fossil bones and teeth. 



If the hypothesis of the agency of man be unacceptable on its present slender founda- 

 tion, geological evidence is equally wanting to apply to the condition of extinction 

 propounded in the following paragraphs: — "In proportion to the bulk of a species is 



* For a discussion of the common notion from the bulk of extinct animals, especially mammals, " that the 

 races of animals have deteriorated in respect of size," see Transactions of the Zoological Society, 4to, vol. iv. 

 (1850) p. 27. 



b 



