SEC. II PRINCIPLES AND PRACTICE OF CLASSIFICATION 99 



genera, but in largest proportion referable to modern types. Later 

 Tertiary (Pliocene and Post-pliocene) birds are almost all of living 

 genera, and some are apparently of living species. Extinct birds 

 coeval with man, their bones bearing his 

 marks, are found in various caves. Sub-fossil 

 birds' bones occur in shell-heaps (kitchen- 

 middens) and elsewhere, of course contempor- 

 aneous with man, and some of them scarcely 

 prehistoric. One of the oldest of these is the 

 gigantic j^pyomis maximus of Madagascar, of 

 which we have not only the bones, but the 

 egg. The immense Moas, or Dinornithes of 

 New Zealand, were among the later of these 

 to die, portions of skin, feathers, etc., of 

 these great creatures having been found. 

 With the Moa-remains are found those of 

 Harpagornis, a raptorial bird large enough to 

 have preyed upon the Moas. Finally, various 

 birds have been exterminated in historic 

 times, and some of them within the lifetime 

 of persons now living. The Dodo of Mauri- 

 tius, Didusineptm, is the most celebrated one 

 of these, of the living of which we have 

 documentary evidence down to 1681; the 

 Solitaire of Eodriguez, Pezophaps solitarius, 

 the G6ant, Leguatia gigantea, and several 

 others of the same Mascarene group of islands, ^^^ ^^ _ R,,to^t;o„ ^f 

 are in similar case. The Great Auk, Alca uguatia gigantea. After 

 impennis, is supposed to have become extinct ° ^^^ ' 

 in 1844; a species of Parrot, Nestor produdus, was last known to 

 be living in 1851 ; various parrots and other birds have likewise 

 disappeared within a very few years. At least one North American 

 . bird, the Labrador Duck, Camptolcemus labradorius, seems likely 

 soon to follow. (A. Newton, Enaj. Brit, ninth edition, art. 'Birds.') 



§ 2.— PRINCIPLES AND PEACTICE OF CLASSIFICATION 



Having seen what a Bird is, and how it is distinguished from 

 other animals, our next business is to inquire how birds are related 

 to and distinguished from one another, as the basis of 



Classifleation : a prime object of ornithology, without the 

 attainment of which birds, however pleasing they are to the senses, 

 do not satisfy the mind, which always strives to make orderly 



