154 Australian Mastodontoid Pachyderm. 
habits of the extinct Mastodons and Dinotheres, indicate these 
creatures to have been frequenters of marshes, swamps, or 
lakes. Other relations of land and sea than now characterize 
the southern hemisphere, a different condition of the surface 
of the land, and of the meteoric influences governing the pro¬ 
portion and distribution of fresh water on that surface, may, 
therefore, be conjectured to have prevailed, when huge Mas¬ 
todontoid Pachyderms constituted part of the quadruped- 
population of Australia. May not the change from a more 
humid climate to the present peculiarly dry one have been the 
cause, or chief cause, of the extinction of such Pachyderms? 
Was not the ancient Terra Australis, when so populated, of 
greater extent than the present insular continent ? 
The mutual dependencies between large mammalian quadru¬ 
peds, and other members of the animal kingdom, suggest other 
reflections in connexion with the present fossil. If the extinct 
species ever so abounded as to require its redundancy to be 
suppressed by a carnivorous enemy, then some destructive 
species of this kind must have coexisted, of larger dimensions 
than the extinct Dasyu. as laniarius ,—the ancient destroyer of 
the now equally extinct gigantic kangaroos, Macropus Titan , 
&c., whose remains were discovered in the bone-caves of Wel¬ 
lington \ alley. Extremely few coprophagous beetles have 
hitherto, I believe, been found in Australia, and the scarcity of 
such is readily explained by the absence of native species of 
large herbivorous mammals; but the dung of the Mastodon¬ 
toid quadrupeds which formerly existed in Australia must then 
have afforded the requisite conditions for a greater abundance 
of such Coleoptera . These and other speculations are natu¬ 
rally suggested by the highly interesting fossils here described. 
The great importance of such organic remains will be obvious 
from the few inferences which have been here briefly noted: 
our obligations to the enlightened collector and transmitter 
of the Mastodontoid fossils are great, and the arrival of ad¬ 
ditional facts and specimens will be most earnestly welcomed. 
I have the honour to be, Gentlemen, 
Your most obedient servant, 
Richard Owen. 
London , Nov. 1,1842. 
NETTLES. 
There can be little doubt but that the nettle, which is so 
common about the stockyards of the Colony, is an imported 
species—the Urtica dioica —which is stated by botanists to 
be indigenous to Europe, Asia, and America; but it does not 
appear that any of the early visitants of these Colonies observed 
it in any part of Australia. 
