the family of Cuculida. 
217 
like the Frigate Pelicans, the jagars, and some of the eagles, rob 
other birds of their food ; but this is a mere act of thieving, for all 
these feathered robbers can, and do habitually depend just as much 
upon their own industry in procuring food. But with the typi- 
cal cuckoos the case is far different, for by depositing their eggs 
in the nest of other birds, to whom they leave the care of hatch- 
ing their young and feeding them afterwards, they become as truly 
parasitic as any of the Acari or Pediculi ; they fasten themselves, as 
it were, on another living animal, whose animal heat brings their 
young into life, whose food they alone live upon, and whose death 
would cause theirs, during the period of infancy. Such only is a pa- 
rasitic animal, and such only, among birds, belong to the typical 
cuckoos, and their representative the Molothrus pecoris. 
Such may be considered the leading or most typical distinctions 
of the family now before us, as furnished by that particular group 
which stands at the head, and of which our English species is a per- 
fect example. As we descend more into detail, and investigate the 
peculiarities which distinguish the minor divisions, we shall find all 
those variations of structure and of economy which is to be met with 
in every other natural group of birds, following in the same uniform 
series as the primary types of the animal kingdom. Before, however, 
we proceed further, it will be satisfactory to show how perfectly the 
conclusion we have come to, on the aberrant rank of the family, is 
supported by the following table ; wherein the five families of the 
Scansores are arranged under the three primary divisions of the 
tribe. 
ANALOGIES OF THE SCANSORES on CLIMBERS. 
Families of the 
Scansores. 
i r 
- 
Typical characters. 
Tribes of the 
Insessores. 
Orders of 
Birds. 
-3 
<{ PsiTTACID^i, 
3 f fBill lengthen 
p > ^r 
Bill short, with a 
j distinct notch or 
tooth, 
lengthened, co-~| 
nncfFile f*n\rf*r I 
t 
I CERTHlAD.li, ' 
CUCULID^:, 
Leu. wit ii 
feathers, J 
Nostrils protected by \ 
a corneous scale, j" 
" Feet not strictly scan-1 
serial, very shorten os- '. 
trilsnaked,tail.covers j 
remarkably long, J 
RAMPHASTID^E 
DENTIROSTRES. RAPTORES. 
CONIROSTRE'S. INSESSORES. 
SCANSORES. RASORES. 
GRALLATORES. 
NATATORES. 
We see in this table a precision and harmony which is not to be 
