236 EXTINCT MONSTERS. 



plaster cast of an egg found in certain surface deposits in 

 Madagascar. In the same case may be seen bones of the Dodo 

 from the isle of Mauritius. Unlike New Zealand, Madagascar 

 possesses no living wingless bird. But in the neighbouring island 

 of Mauritius the Dodo has been exterminated less than three 

 centuries ago. The little island of Rodriguez, in the same 

 geographical province, has also lost its wingless Solitaire. 



It will thus be seen that we have three distinct groups of giant 

 land birds — the Moas, the Dromornis, and the ^pyornis, — occu- 

 pying areas at present widely separated by the ocean. 



This raises the difficult but very interesting question, how they 

 got there ; and the same applies to their living ancestors. The 

 ostrich proper, Struthio camelus, inhabits Africa and Arabia; but 

 there is evidence from history to show that it formerly existed in 

 Beluchistan and Central Asia. And, going still further back, the 

 geological record informs us that, in the Pliocene period, they 

 inhabited what is now Northern India. In Australia we have 

 the Cassowary (Casuarius) and the Emeu (Dromaius) ; in New 

 Zealand, the Apteryx (or Kiwi). Now, as none of these birds can 

 either fly or swim, it is impossible that they could have reached 

 these regions separated as they now are ; and it is hardly 

 likely that they arose spontaneously in each district from 

 totally different ancestors. But the new doctrine of evolution 

 affords a key to the problem, and tells us that they all sprang 

 from a common ancestor, of the struthious type (probably 

 inhabiting the great northern continental area), and gradually 

 migrated south along land areas now submerged. In this way 

 we get some idea of the vast changes that have taken place in 

 the geography of the world during later geological periods. 

 Perhaps they were compelled to move south until they reached 

 abodes free from carnivorous enemies. Having done so, they 

 evidently flourished abundantly, especially in New Zealand, where 

 there are so few mammals, except those recently introduced 

 by man. 



