250 ON THE CLASSIFICATION OF BIBOS. 
mediate access to all his specimens for the purpose of 
comparison, and he will therefore trust more to memory 
than to actual examination. Unless, therefore, he is a 
very nice and cautious observer, he will be frequently 
deceived. Colour, of course, is one of the best, or, at 
least, one of the most obvious distinctions of species ; hut 
it is by no means the only one ; and, in some particular 
tribes, it is none at all. The whole of the drongo 
shrikes {EdoUnce) are entirely of a black colour, more 
or less glossy, with a tail more or less forked. At 
first sight the greater part appear to be the same, and 
yet we possess near fifteen species, from various parts 
of the old world, which are quite distinct. The tree- 
creepers, again, of tropical America, forming the en- 
tire genus Dendrocolaptcs, have all precisely the same 
coloured plumage, and yet we already know of near 
twenty species, distinguished by their size, and the com- 
parative length, shape, and curvature of their bills. The 
American flycatchers, both large and small, can only be 
discriminated when compared with each other after they 
are preserved, or by close attention to their different 
habits and notes when alive, di e wish not to advocate 
indiscriminate slaughter, but whenever the sportsman 
observes any shade of difference in the manners of a 
bird from that species which he conceives it to be, he 
should secure the specimen, preserve it, and record its 
peculiarity in his note-book. We always made it a point 
of conscience never to throw away a bird after it had 
been killed ; considering that its life would then have 
been taken wantonly, and without any benefit either to 
science or to useful information. 
(211.) We may now proceed to notice the countries 
whose ornithology requires the most investigation, and 
where the collector will be most likely to meet with new 
or interesting species. For this purpose we shall take a 
rapid survey of the five zoological provinces of the 
world here characterised ; viz. Europe, Asia, Africa, 
America, and Australia ; introducing under each head 
such remarks as may serve to direct the attention of the 
