362 PRACTICAL AND SCIENTIFIC ZOOLOGY. 
fectly formed, that you can have no hesitation in ex- 
cluding them from the Curtipedes ; while their compressed 
bill, destitute of that thickened, conic form which be- 
longs to the Conirostres, indicates, on the other hand, 
that they still form a part of the Dentirostres. Again, if 
we were merely to judge of the natural station of the 
short-legged thrushes (Brachypodine), the orioles ( Orio- 
line), or the flycatchers (Todide), by the length of 
their feet, we should class them in the order Curtipedes : 
but then, the very distinct manner in which their bills 
are notched must be taken into consideration ; and, as 
this character is so very conspicuous, it is sufficient to 
point out that they are of the tooth-billed families, not- 
withstanding their short feet: they are, in fact, aber- 
yant groups; and all the aberrant groups have only 
some, not all, of the typical characters—just as a horn- 
less cow is still a cow, although it has no horns. 
(447.) Having now acquired a general idea of the 
Dentirostral division as a whole, read over the cha- 
racters of the families, and learn their chief distinctions. 
If you could get the skins of a shrike, thrush, warbler, 
chatterer, and flycatcher, you would then have examples 
before you of each family, and might compare them 
with what you read of each. For the present, 1 must 
refer you, for this information, to “‘ Northern Zoology,” 
where a good deal is said about each of these families : 
but, when I finish the ornithological volume of this 
series, you will want no other introduction to my views 
of arrangement. From the families you proceed, of 
course, to the genera and the sub-genera; thus gradually 
descending from one circle to another, and getting 
general ideas on the nature of each ; without, however, 
endeavouring to commit to memory, as you would do a 
lesson, all that you read. 
(448.) But nothing will make this plan of proceeding 
more intelligible to you than taking an example. Suppose, 
therefore, we select the common blue titmouse (Parus 
ceruleus L.), asa bird whose family, genus, and species 
you wish to make out. First, you look to the primary 
