Let us pause for a few moments at the solemn passages where life uncertain seems still to oscillate, where Nature appears to question herself, to examine her own volition. "Shall I be fish or mammal?" says the creature. It falters, and remains a fish, but warm-blooded; belongs to the mild race of lamentins and seals. "Shall I be bird or quadruped?" A great question; a perplexed hesitancy--a prolonged and changeful combat. All its various phases are discussed; the diverse solutions of the problems naïvely suggested and realized by fantastic beings like the ornithorhynchus, which has nothing of the bird but the beak; like the poor bat, a tender and innocent animal in its family-circle, but whose undefined form makes it grim-looking and unfortunate. You perceive that nature has sought in it _the wing_, and found only a hideous membranous skin, which nevertheless performs a wing's function:
Yes; but even the wing does not make the bird.
Place yourself towards the centre of the museum, and close to the clock. There you perceive, on your left, the first rudiment of the wing in the penguin of the southern pole, and its brother, the Arctic auk, one degree more developed; scaly winglets, whose glittering feathers rather recall the fish than the bird. On land the creature is feeble; but while earth is difficult for it, air is impossible. Do not complain too warmly. Its prescient mother destines it for the Polar Seas, where it will only need to paddle. She clothes it carefully in a fine coat of fat and an impenetrable covering. She will have it warm among the icebergs. Which is the better means? It seems as if she had hesitated, had wavered. By the side of the booby we see with surprise an essay at quite another genus, yet one not less remarkable as a maternal precaution. I refer to a very rare gorfou--which I have seen in no other museum--attired in the rough skin of a quadruped, resembling a goat's fleece, but more shining, perhaps, in the living animal, and certainly impermeable to water.
To link together the birds which do not fly, we must find the connecting point in the navigator of the desert--the bird-camel, the ostrich, resembling the camel itself in its internal structure. At least, if its imperfect wings cannot raise it above the earth, they assist it powerfully in walking, and endow it with extraordinary swiftness: it is the sail with which it skims its arid African ocean.