It has been thought that the humming-bird has no wish-bone, its frame being more compact than such construction would allow, in order to withstand the immense strain of its wings--immense, yes, measured by millimeters. At any rate the largest organ is the breast muscle, and the heart is three times as large as the stomach. Its senses are alert, and a well developed skull could prove the excellence of the brain beneath did not its habits do so. The humming-bird always trusts itself to the air for however brief a distance, and flings its supple body about from one flower to another in vibrating flight. Now it hovers near without disordering a petal, now it hangs from tall grasses by the tip of its thornlike bill, a sparkling of wings with spurts of precious stones in a setting of petals, lost in another instant in wide air. Never smutted by earth, because never touching it, the humming-bird juggles among the flowers. It never follows all the flowers of a single bush nor even exhausts all the sweetness of a single flower--“a dart, a glance, a sip, and away;” butterflies, a symbol of caprice, are not more fickle. This utterly erratic creature performing its aerial gambols holds within itself the reason for its being unmolested by any enemy--the chase not being worth the morsel! Ineffable is the whole field of its labor. The coarsest materials of its nests are the finest straws it can pick up. Inside they are lined with down and spiders’ webs. Consistently they are attached to a pendent branch or long-swinging vine. Thither the humming-bird flies to supply a family’s microscopic wants. To a giant looking through a microscope, what a revelation of the infinite industry of nature in worlds beyond the grasp of any sense of his, the humming-bird would be! CHAPTER IV ANIMALS OF DARKNESS AND LIGHT I What a land of silence! The vast forest seems wholly uninhabited save for the chatter of a passing train of harlequin parrots or angry apes. And yet it is not silence. There is the great movement of lapsing and becoming perpetually going on; both composition and decomposition rustling on toward completion. They are mere phases of that “illimitable sun force which destroys as swiftly as it generates and generates again as swiftly as it destroys.” “So fast do the flowers expand that an actual heat, which may be tested by the thermometer, is given off during fructification.” The tepid water forces all growing things to prodigious size. Exuberance seems to have no boundaries. The length of the young shoots is only less amazing than their growth in a single day. Leaves expand until they are twenty feet long, and ferns tangle their own fronds in haste to push out to the utmost limit of their nature. One sees things growing in the damp heat as one hears a yucca palm grow.