Here is an extraordinary plant. Though no thicker than your little finger, it will be found almost a quarter of a mile in length.[55] This is a kind of Cane (_Calamus_); its slender jointed and polished stem is encased in the closely-sheathing and tubular bases of the leaves, which are spiny on their midribs, spiny on their pinnae, and horridly spiny on the long and tough whip-lash in which the point of each leaf terminates. This lengthened cord is studded, at intervals of a few inches, with whorls of stout and acute prickles which are hooked backwards, and performs an important part in the economy of the plant. We see how it sprawls along the ground a few yards, then climbs up a tall tree, runs over the summit, descends on the opposite side to the ground, mounts over another tree, and thus pursues its wormlike course. Now as the pinnate leaves are put forth at every joint, the formidably armed flagellum affords a secure holdfast to the climbing stem, which otherwise would be liable to be blown prostrate by the first gust of wind; the recurved hooks, however, catch in the leaves and twigs of the trees, and effectually maintain the domination of the prickly intruder. It is obvious that every inch sprawled over by this trailing stem supposes all the previous inches of its lengthening course; that every successive joint implies the existence of all the earlier joints; that every whorl of spines involves the development of every former whorl. Yet our reasoning is at fault; there has been as yet no succession; the development has been simultaneous, for it is the development, not of growth, but of creation. Enough of Palms. Look at this _Agave_. Its thick, fleshy, glaucous leaves, with spinous margins and pointed ends, are arranged in many whorls on the summit of a stem, which is scarcely visible, as it barely rises above the soil. From the centre of the crown springs the stately flower-stalk, itself a tree of forty feet in stature, having a cluster of yellow blossoms at the extremities of its candelabra-like branches. Have we here any clue to the past history of the plant? The tall flower-stalk, it is true, is of rapid growth, its whole stature having been attained within three or four weeks. But those massive leaves! Each of these lasts many years, and their development is as slow as that of the flower-stalk is rapid. Certainly we cannot assign to this individual, in the very vigour of its inflorescence, an antiquity less than half a century, and perhaps it may be considerably more. You are altogether wrong; for it is but just called into existence. [Illustration: TRAVELLER'S TREE.]