The great point, therefore, which is at issue, and upon which the natural arrangement
of the entire order of Insessores absolutely depends, is this: Are the Edo-
lianse or the Thamnophilinae one of the typical groups in the family of Laniadae ?
It has been perfectly demonstrated by Mr. MacLeay (and we might give
numerous examples from the animal kingdom in corroboration of the fact), that the
two typical groups of every circle bear a close aud intimate analogy, no less
than a direct affinity, to each other; and that, when such groups are perfect, that
is, when the five leading forms in each have been detected, this relation of
analogy will be fully apparent between each. This, in truth, is perhaps the best,
as it certainly is one of the most severe tests, by which any supposed series of
natural relations can be tried. For although the naturalist, by the synthetic method,
is perpetually in danger of confounding analogy with affinity ; of taking that
to be a form of transition, which subsequently proves to be one of representation;
yet the strongest prejudice in favour of any preconceived notion can never so far
blind his judgment as to produce a double series of groups, having direct analogies
one to the other, and at the same time a positive affinity. Had the labours of
the profound observer who first detected this property of natural groups achieved
nothing more than this discovery, he would have deserved the lasting gratitude
of all succeeding naturalists.
Now if the five types of form among the Lanianae and the Edolianae, or between
the Lanianae and the Thamnophilinae, had been detected, the question might
at once be set at rest; but, unfortunately, this is not the case; and we must therefore
inquire what characters of structure, or what peculiarities of habit, are shared
in common between a Lanius, a Thamnophilus, and an Edolius. The respective
peculiarities of each we shall now draw up in opposite columns, for the sake of
greater perspicuity.
Lanius, Jbinn.
Bill hard, universally short,
entirely compressed, the cul-
men arched from the base;
the upper mandible furnished
with a distinct and prominent
tooth; the lower mandible
thick and ascending.
Thamnophilus, Vieil.
EXTERNAL ORGANIZATION.
Bill hard, more lengthened,
but entirely compressed, the
culmen curved only at the
end ; the upper mandible furnished
with a distinct and
sometimes prominent tooth,
but smaller than that of Lanius
; lower mandible thick
and ascending.
Edolius, Cuv.
Bill not strong, generally
short, but sometimes lengthened,
compressed only on its
side, the base broad, culmen
arched from the base; upper
mandible notched, but destitute
of any tooth; lower mandible
weak, straight, not ascending.
Lanius, Im n .
Feet strong; the tarsi considerably
longer than the hind
toe.
Wings rounded, of moderate
length.
Food. Carnivorous and
insectivorous.
Solitary, or living only in
pairs.
Watch for their prey from a
fixed station.
Seize their food with their
claws *, and devour it at leisure
when at rest.
Prey upon small birds, insects,
and less organized animals.
Thamnophilus, Vieil.
EX TERN A L ORGANIZATION.
Feet strong; the tarsi considerably
longer than the hind
toe; the two outer toes frequently
connected at their
base.
Wings rounded, shorter and
more feeble than those of Lanius.
HABITS.
Food. Carnivorous and
insectivorous.
Solitary, or living only in
pairs.
Search for their prey in
foliage.
Seize their prey (in all probability)
with their bill.
Prowl in thickets after the
eggs and young of other birds,
and attack such as are weak
or sickly, as well as insects
and less organized animals.
Edolius, Cu v.
Feet slender, short; the
tarsi scarcely longer than the
hind toe.
Wings lengthened, but the
three first quills graduated.
Food. Insectivorous.
Social, congregating in
large flocks.
Search for their food during
flight.
Seize their food with their
bifl.
Prey entirely upon bees and
small winged insects.
Now if Lanius be a typical group, we can be at no loss to discover which of
these is most related to it by affinity ; more particularly as in the two other divisions,
namely, the Ceblepyrinac and the Tyranninae, the feet are equally short
with those of the Edolianae. But although, from our present imperfect knowledge
of these birds, we are still ignorant of the five leading forms, or rather genera, in
each of the sub-families of Lanianae, Thamnophilinae, and Edolianae, still we may
compare the contents of the whole family with that of the Merulidae. For as
both are unquestionably the typical groups of the Dentirostres, their sub-families,
* This we have, in one personally witnessed; and the fact is also confirmed by the friend Mr. Audubon. observations of our
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