CUCKOOS. 
3 
a perpendicular attitude, to explore the bark, and de- 
tect the external signs that may appear of its insect- 
food lurking within. 
But there are other forms of climbing feet besides 
that of the AV^oodpecker, ecpially adapted for perpendi- 
cular ascent, having three toes in front and one be- 
hind, the hinder one having its claw lengthened and 
more powerfully developed ; these will be noticed 
when we consider the family CerthiadcB, or Creepers. 
Birds of very different form, size, and appearance 
are brought together in this tribe ; we have the 
Cuckoos [CaculidcB], the Toucans iJRampliastidce)^ the 
Parrots {^Psittacidm), the Woodpeckers {Picida:), and. 
the Creepers {Certliiadm) . According to this arrange- 
ment, the Cuckoos and the Creepers form the aberrant 
groups, while the Parrots hold the typical station, 
which, from the intelligence they display, their great 
facility of climbing about trees, and moreover their 
peculiar and distinct characters, which render them 
the most isolated group of the whole class, we con- 
sider them most fit to occupy. The AVoodpeckers 
and Toucans therefore fall under the denomination of 
sub-typical groups. 
In writing of the Fissirostres, we were engaged Avith 
that form of birds more particularly adapted for feed- 
ing upon winged insects which are caught in the air ; 
here Ave have to consider a very different development 
of form and poAvers. In the fissirostral birds, Avhere 
the feet Avere not required to assist them in pro- 
curing their sustenance, those members AA^ere com- 
paratumly feeble, and their only purpose Ave observed 
Avas to support the body upon a perch Avhilst the bird 
