BY SYDNEY B. J. SKERTCHLY. 73 
strenuous conditions of climate, the bats from their powers 
of flight, and the mice and rats, which are not only capable 
of thriving on dry food, but can do with a minimum of water 
—indeed some never drink at all. This is surely significant. 
63. As every zoologist admits, our Marsupials and 
Monotremes taken together, and still more if the latter 
are left out, are not comparable with the individual placental 
orders, but represent them in bulk. Thus we have carnivora 
represented by such forms as Dasyurus, our Native Cats, 
herbivora by all kinds from the kangaroos of the plains 
to the tree-wallaby of N. Queensland and New Guinea ; 
rodents are represented by the wombat, edentata by 
Myrmecobius, and so we may go on. Indeed the Metatheria 
(to use Huxley’s terms) are comparable rather with the 
Kutheria than with any Family or Order thereof. 
64. This indicates immense modification, and as it has 
been an axiom of most evolutionists that species are of such 
slow growth that even a geological era may not be long 
enough to produce one, we find even such careful reasoners 
as Wallace writing, *‘ As, however, no other form than that 
of the Didelphyidae occurs there (Europe) during the 
Tertiary period, we must suppose that it was at a far more 
remote epoch that the ancestral forms of all the other 
marsupials entered Australia.” Now this is not so much 
explaining a difficulty, as explaining it away. It assumes 
as true the slow evolution of species, and argues from this 
assumption that our diprotodont marsupials must have 
had a very remote ancestry a long way off. As far as real 
evidence goes, the assumption is as baseless as the deduction. 
The rocks are full of evidence of rapid origin of species : 
the outburst of Ammonites in the Jurassic, the irruption 
of all sorts of mammals after the close of the Cretaceous— 
one can find any number of cases in point—and never one 
to show anything else but rapidity as to the origin of 
Species. 
65. The simple facts are, that the Australian marsupials 
did come on suddenly : they did not enter Australia in the 
dim Mesozoic ages: they never did live elsewhere. This 
is what geology asserts : the other is what geologists assume. 
We have, on strict examination of the facts, arrived at an 
impasse, just as we did in the case of the Flora. Surely 
