ure
is repeated; but, as was to have been expected, with two main differences.

First, that in the lower grade the reproductions themselves seem merged in
those of irritability, from the very circumstance that the latter
constitutes no pole, either to the former, or to sensibility. The force of
irritability acts, therefore, in the insect world, in full predominance;
while the emergence of sensibility in the fish calls forth the opposite
pole of reproduction, as a _distinct_ power, and causes therefore the
irritability to flow, in part, into the power of reproduction. The second
result of this ascent is the direction of the organizing power, _ad
intra_, with the consequent greater simplicity of the exterior form, and
the substitution of condensed and flexible force, with comparative unity
of implements, for that variety of tools, almost as numerous as the
several objects to which they are to be applied, which arises from, and
characterises, the superficial life of the insect creation. This grade of
ascension, however, like the former, is accompanied by an apparent
retrograde movement. For from this very accession of vital intensity we
must account for the absence in the fishes of all the formative, or rather
(if our language will permit it) _fabricative_ instincts. How could it be
otherwise? These instincts are the surplus and projection of the
organizing power in the direction _ad extra_, and could not, therefore,
have been expected in the class of animals that represent the first
intuitive effort of organization, and are themselves the product of its
first movement in the direction _ad intra_. But Nature never loses what
she has once learnt, though in the acquirement of each new power she
intermits, or performs less energetically, the act immediately preceding.
She often drops a faculty, but never fails to pick it up again. She may
seem forgetful and absent, but it is only to recollect herself with
_additional_, as well as _recruited_ vigour, in some after and higher
state; as if the sleep of powers, as well as of bodies, were the season
and condition of their growth. Accordingly, we find these instincts again,
and with them a wonderful synthesis of fish and insect, as a higher third,
in the feathered inhabitants of the air. Nay, she seems to have gone yet
further back, and having given B + C = D in the birds, so to have sported
with one solitary instance of B + D = A in that curious animal the dragon,
the anatomy of wh