FBINCIPLES AND PRACTICE OF CLASSIFICATION. 
65 
of them scarcely pre-historic. One of the oldest of these is the gigantic JEpyornis 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 sldn, 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 life-time of persons now living. The Dodo of 
Mauritius, Didus ineptus, is the most celebrated one of these, of 
the living of which we have documentary evidence down to 1681 ; 
the Solitaire of Kodriguez, Pezophaps soUtaruis, the Geant, Leguatia 
gigantea, and several others of the same Mascarene group of islands, 
are in similar case. The Great Auk, Alca impennis, is supposed 
to have become extinct in 1844 ; a species of Parrot, Nestor pro- 
diictuSf was last known to be living in 1851; various parrots and 
other birds have likevidse disappeared within a very few years. 
At least one North American bird, the Labrador Duck, Camp- 
tol(Bmus lahradorius, seems likely soon to follow. (A. Newton, 
Ency. Brit, 9th ed., art. Birds.) 
§ 2. — PRINCIPLES AND PRACTICE 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 
Classification : 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 disposition of its knowledge, and so discover the reciprocal relations and interdepen- 
deneies of the things it knows. Classification presupposes that there do exist such relations, 
according to which we may arrange objects in the manner which facilitates their comprehen- 
sion, by bringing together what is like, and separating what is unlike ; and that such relations 
are the results of fixed, inevitable law. It is, therefore. 
Taxonomy (Gr. ra|ts, taxis, arrangement, and vofios, nomos, law), or the rational, 
lawful disposition of observed facts. Just as taxidermy is the art of fixing a bird's skin in a 
natural manner, so taxonomy is the science of arranging birds in the most natural manner; 
in the way that brings out most clearly their natural affinities, and so shows them in their 
proper relations to each other. This is the greatest possible help to the memory in its 
attempt to retain its hold upon great numbers of facts. But taxonomy, which involves 
•consideration of the greatest problems of ornithology, as of every other branch of biology 
(biology being the science of life and living things in general), is beset with the gravest difficul- 
ties, springing from our defective knowledge. We could only perfect our taxonomy by 
having before us a specimen of every kind of bird that exists, or ever existed; and by 
thoroughly understanding how each is related to and differs from every other one. This is 
obviously impossible ; in point of fact, we do not know all the birds now living, and only a 
small number of extinct birds have come to light ; so that many of the most important links 
in the chain of evidence are missing, and many more cannot be satisfactorily joined together. 
With these springs of ignorance and sources of error must be reckoned also the risk of going 
5 
Fig. 17. — Restoration of 
Leguatia gigantea. From 
Packard, after Schlegel. 
