from the seed-leaflets, or cotyledons, through the stalk, the leaves, and the calyx, into the perfect flower, the various colours of which seem made for the reflection of light, as the antecedent grade to the burnished scales, and scale-like eyes of the insect. Nevertheless, with all this seeming prodigality of organic power, the whole tendency is ad extra, and the life of insects, as electricity in the quadrate, acts chiefly on the superficies of their bodies, to which we may add the negative proof arising from the absence of sensibility. It is well known, that the two halves of a divided insect have continued to perform, or attempt, each their separate functions, the trunkless head feeding with its accustomed voracity, while the headless trunk has exhibited its appropriate excitability to the sexual influence.
The intropulsive force, that sends the ossification inward as to the centre, is reserved for a yet higher step, and this we find embodied in the class of fishes. Even here, however, the process still seems imperfect, and (as it were) initiatory. The skeleton has left the surface, indeed, but the bones approach to the nature of gristle. To feel the truth of this, we need only compare the most perfect bone of a fish with the thigh-bones of the mammalia, and the distinctness with which the latter manifest the co-presence of the magnetic power in its solid parietes, of the electrical in its branching arteries, and of the third greatest power, viz., the qualitative and interior, in its marrow. The senses of fish are more distinct than those of insects. Thus, the intensity of its sense of smell has been placed beyond doubt, and rises in the extent of its sphere far beyond the irritable sense, or the
