38 ON THE CLASSIFICATION OP BIRDS. 
open and shut his fine ytllow crest, when merely occu- 
pied in watching for insects. This fact, joined with the 
considerations already mentioned, has more than once 
suggested to us the idea that these 
flower-like ornaments are occa- 
sionally used as snares, to attract 
the attention of insects, so as to 
bring them within reach of being 
captured by a sudden dart. This, 
at least, we know, — that insects 
are attracted by the bright colours 
of flowers, and turn out of their 
course to visit them. It is, there- 
fore, not too much to suppose 
that, seeing what, at a little dis- 
tance, appears to them a bright yellow flower, they 
should fly towards it, discovering their mistake only 
when they are within the rahge of the sudden swoop 
of their treacherous enemy. It by no means follows 
that this is the habit of all flycatchers ; for in pro- 
portion to the variety in the difierent races of insects, so 
are the birds which feed upon them endowed with dif- 
ferent instincts, and pursue different modes in their 
capture. Be this hypothesis, however, true or false, the 
facts upon which it is founded are beyond cavU, and we 
must leave those who are not disposed to admit the infer- 
ences we draw from them, to discover some more plausible 
mode of accounting for the facts we have stated. 
(46.) The only native birds which possess a crest in 
any way analogous to those of the tyrants, are the gold 
crests, the pre-eminent types of the whole family of 
SyMadm, or warblers. The crests, however, of these 
little creatures cannot be strictly termed concealed, for 
this ornament is conspicuous, even when the feathers 
lie flat upon the head ; it is, in fact, a union of this form 
and of the first we noticed. Several of the North 
American warblers, forming the genus Sylmcnla, have 
what may he called incipient crests of this sort, indi- 
cated by a stripe of bright yeUow down the middle. If 
