174 ON THE CtASSIFICATION OP BIRDS. 
in temperate and uncertain climates like our own ; or 
where there was little or no sand to protect them from 
observation and external injury. Hence it is that 
nature has endowed these little architects with an 
instinctive knowledge of fabricating temporary abodes, 
which are often patterns of skill and contrivance ; and, 
when we consider the fabricators, almost miracles of 
execution. And yet this faculty, like most others, is 
neither given to all, or in the same degree to such as 
possess it. Hence we see as great a variety in tlie.form 
and construction of nests, as in the situations in which 
they are placed. All writers on the subject have ob- 
served this, which is indeed apparent even among our 
native birds ; but no one seems to have had any idea 
that in tliis infinite diversity, there is every reason to 
believe as much order and system exists as can be found 
in the form and structure of the birds themselves. 
Some birds build in trees, some upon the ground, some 
beneath the surface, and some not at all. Each of these 
again present us with a diversity of operations, of forms, 
and of circumstances, all calculated to display tliat end- 
less and astonishing variety which gives such a charm 
to creation, and silently, though emphatically, speaks of 
its great and wonderful Author. 
(150.) We shall commence our remarks on the sub- 
ject with such birds as build their nests upon trees, and 
which may be therefore termed arboreal. Of these 
there are many sorts, differing both in form, construc- 
tion, and situation. Now as this art is one of the grand 
characteristics of the feathered creation, we are naturally 
led, by analogy of reasoning, to expect that it will be most 
conspicuous in that particular order which shows us, in 
every other quality, the perfection of the class. In this 
we shall not be disappointed ; for the most elaborately 
constructed nests are those of the 1 nsessorial birds ; that 
order, in fact, which is pre-eminent both in faculties, 
in song, and in building. Previous, however, to enter- 
ing upon this extensive order, we shall briefly notice that 
of the Raptores, or birds of prey, premising that in 
