HINTS TO ORNITHOLOGISTS. 317 
' diet of the wigeon is grass. Still, neither the wigeoDj 
Ifcor the barn-door fowl, have bristles at the beak. 
The claws of rapacious birds are pronounced to 
be " retractile." If they are so, then the knowledge 
of internal anatomy would force us to pronounce 
the claws of other tribes of birds, such as the 
.i robins, the doves, the barn-door fowls, and a thou- 
sand others, to be retractile. 
The soldier must spend many a day amid the 
roar of hostile cannon, before he becomes qualified 
to command an army ; the carpenter ought to 
i work for years in the dock-yard, ere he attempts to 
build a line-of-battle ship; and the schoolmaster 
has to pore over many a scientific volume, in order 
to prepare himself to teach the mathematics. 
But, somehow or other^ it happens, nowadays, 
that practical knowledge does not seem to be con- 
sidered essentially necessary for those who under- 
( take to write on certain parts of Natural History. 
Thus, some there are who will offer their history 
of birds to the public, although it can be ascer- 
tained that they have never been in the country 
which those birds inhabit. Others again^ not 
having resided a sufficient length of time amongst 
the foreign birds which they undertake to describe, 
are perpetually giving statements at variance with 
the real habits of the birds. Thus the account 
i which is given us of the habits of the Toucan is 
wrong at all points ; to say nothing of its tongue, &c* 
No man who has paid sufficient attention to' the 
woodpeckers whilst in quest of food, will allow him- 
