4 
BEAUTIFUL BIRDS. 
was at rest. In the present group the feet become 
essential instruments in aiding the birds to maintain a 
footing in tliose places where their food is alone 
to be procured, and their size and strength are pro- 
portionally developed. The hill, instead of being 
weak and broad at the base, in order to be serviceable 
in catching without injuring the flying insect, is much 
compressed and strengthened ; so much so, that some 
of the species are enabled to strike ivuth it against 
the bark of a tree wdth considerable force, and to ex- 
cavate a hole in the solid wood. It becomes a service- 
able instrument, in some instances, in assisting the 
progress of the bird amongst the branches, as efficient 
as the foot itself, and is employed in extricating from 
the hard shell the kernel of fruits. In the aberrant 
group, leading into the succeeding tribe of slender- 
billed birds, Tenuirostres, the bill is attenuated and 
of a delicate structure, and the toes are arranged in a 
similar manner to the generality of insessorial birds ; 
thus exhibiting an approximation to the suctorial 
order of the Tenuirostres^ and continuing the chain of 
progressive affinity. 
Tlie generic characters of the family CuculidcB, by 
which w'e enter the tribe of scansorial birds, cannot 
be well defined, so as to include the whole of the 
genera, on account of the diversity of form that ob- 
tains amongst the members of it. The bill is gene- 
rally slender, somewhat compressed, broad at the base, 
and, in the typical species, slightly curved, the lower 
mandible following tlie curve of the upper ; the nos- 
trils basal, round, and margined with a prominent 
membrane. The legs short, toes arranged in pairs ; 
