When food was scarce the Dryopithecus became a nomad, a sort of four-handed Odysseus who was very well able to fight his own battles, whether he wielded a heavy stick, or hugged his foe, or from the shelter of a tree dropped missiles that cracked heads and made backbones exceedingly painful. Hugging seems to have been his _forte_, after clawing and fierce blows had prepared the way for a close embrace; and by his expert ferocity in defence and in attack he earned for himself the right to be a forerunner of several entertaining creatures, notably the gorilla and the chimpanzee and primitive man. He was inquisitive enough to use every natural bridge put in his path by good fortune. At first I see him on four sorts of natural bridge, and no fault can be found with his activity. He crawls along fallen trees over some torrents and chasms; across a flooded river here and there he leaps in a shambling, lopsided fashion, when stepping-stones and boulders rise above water-level; he roams into hilly districts where many a ledge of rock spans a dangerous gap; but he enjoys himself most of all when a suspension bridge of branches enables him to amble from tree to tree across a deep-lying river pent up between high cliffs. In these four bridges, each of them generic, Nature has arrived at utility in her usual manner, by alternating growth and violence. The fallen tree, for instance, from which all timber bridges have been evolved by handicraft in a sequence of gradual improvements, belongs to the utility of Nature’s violent moods; and this applies also to the bridge of stepping-stones. Earthquakes and floods distributed boulders over the beds of rivers, and from these boulders handicraft has developed piers and abutments. On the other hand, a bridge of long boughs--and I have used many a one myself--is a symbol not merely of growth but of abundance, and also of endurance. But it is not to be looked upon as the only suspension bridge along which our arboreal ancestry capered, and from which primitive mankind took, and take, hints in bridge-building. Let us remember also the pendent bridge of lianes, and of other tough creeping plants, which in many warm countries grew, and grow, from tree to tree, forming strong cables. On such a high-swung bridge I can see the Dryopithecus, suspended by his hands, and learning tricks as a gymnast, while his mate squats between the fork of a branch and collects fleas from her baby.