ogv THE HISTORY OF THE MO AS. 589 



and probably Upper Miocene, while the Hon. W. Mantell found in 

 1849 a fragment of a bone, which probably belonged to a Moa, near 

 Moeraki in beds of Lower Miocene age.' 



The Ratitae are generally supposed to have originated in the 

 Northern Hemisphere, and to have spread southwards into Pata- 

 gonia, South Africa, Australia, and New Zealand. But if so, how 

 could birds which could not fly manage to reach New Zealand with- 

 out being accompanied by any mammalia ? Certainly they did not 

 precede the mammalia, and it is very unlikely that they should 

 twice have swum across straits which were impassable to mammals 

 — once from the Oriental into the Australian region, and again from 

 the Australian region into New Zealand — and there are other reasons 

 for doubting the northern origin of the Australasian Ratitae. The 

 existing New Zealand Ratitae {Apteryx or Kiwi) are smaller than any 

 of the others, and make a nearer approach to the original flying 

 ancestors ; and we should expect to find the smallest and least 

 altered forms near the place of origin. Now there are in Central 

 and South America a group of birds called Tinamus, which, although 

 flying birds, have been shown by the late Professor W. K. Parker 

 to resemble the Australasian Ratitae in many particulars, and as the 

 connection between South America and New Zealand is well known, 

 it seems more probable that the Moas originated in New Zealand in 

 the Eocene period, from flying birds related to the Tinamus, and 

 that they spread from here into Australia and New Guinea, than that 

 they should have migrated southward from Asia. 



In whatever way the Moas originated in New Zealand, it is 

 evident that the land was a favourable one, for they multiplied 

 enormously and spread from one end to the other. Not only was the 

 number of individuals very large, but they belonged to no less than 

 seven genera, containing twenty-five different species, a remarkable 

 fact which is unparalleled in any other part of the world. Africa and 

 Arabia are inhabited by but two or three species of Ostrich ; South 

 America, from Peru to Patagonia, has only three species of Rhea ; 

 Australia has two species of Emu and one Cassowary ; while eight 

 other species of Cassowary inhabit islands from New Britain to 

 Ceram. Outside New Zealand two species of Ratitae are rarely 

 found living in the same district, while a few hundred years ago there 

 were in New Zealand several different kinds of Kiwi, as well as the 

 twenty-five species of Moas. An explanation of this problem may 

 perhaps be found by examining the present distribution of the Casso- 

 waries. Here we have eight species inhabiting five different islands, 

 and if this region of the earth were to be elevated, and the islands 

 joined together, these eight species would mingle. If the region were 

 to sink once more, all of them would be driven to the highest land, 

 and might be crowded into one small island. Now we know from 

 geology that New Zealand has gone through a series of changes in 

 1 May be earlier, according to Capt. Hutton's new memoir. — Ed. 



