2 The Bird 



the "j)oems hidden in the bones." As Professor Huxley 

 once said, "Palaeontology is simply the biolog}' of the 

 past, and a fossil animal differs only in this regard from 

 a stuffed one, that the one has been dead longer than 

 the other, for ages instead of for days." 



/A great many more fossil mammals and reptiles have 

 been discovered than birds, and the reason may perhaps 

 be conjectured. The bones and bodies of birds were in 

 former times as now very light, and if death occurred on 

 the water, the body woidd float and probably be de- 

 voured by some aquatic reptile. Then, again, when some 

 cataclysm of nature or change of climate obliterated 

 whole herds and even races of terrestrial creatures, the 

 birds would escape by flight, and when death eventually 

 came, they would be stricken, not in flocks, but singly 

 and in widely scattered places as to-day. 



/I'or perhaps a million years in the past, birds have 

 changed scarcely at all, — the bones of this period belong- 

 ing to tlie species or at least genera of living birds. But 

 in the period known as the Cretaceous, when the gigantic 

 Dinosaurs flourished and those flying reptile-dragons — 

 the PtcrocJactyls — flapped through the air, a few remains 

 of birds have been found. Some of these are so com- 

 plete that almost perfect skeletons have been set up^ 

 enabling us vividly to imagine how the l)ird looked when 

 swimming through the waters of our globe, or flying 

 through the air, perhaps four millions of years ago. 



The most remarkal)le peculiai'ity of these birds was 

 the j)ossession of teeth. Two of the most well-known 

 examples are called Ichthyornis and Hesperornis. The 



