There are two ways of endeavouring to solve this question of the inevitability of death. The first is to examine popular observation, practised, so to speak, unintelligently and without special precautions. The second is to analyze everything we know relative to the conditions of elementary life. CHAPTER IV. THE APPARENT PERENNITY OF COMPLEX INDIVIDUALS. Millenary trees—Plants with a definite rhizome—Vegetables reproduced by cuttings—Animal colonies—Destruction due to extrinsic causes—Difficulty of interpretation. Popular opinion teaches us that living beings have only a transient existence, and as a poet has said: “Life is but a flash between two dark nights.” But, on the other hand, simple observation shows us, or appears to show us, beings whose duration of existence is far longer, and practically illimitable. _Millenary Trees._—We know of trees of venerable antiquity. Among these patriarchs of the vegetable world there is a chestnut tree on Mount Etna which is ten centuries old, and an ivy in Scotland which is said to be thirty centuries old. Trees of 5000 years old are not absolutely unknown. We may mention among those of that age the famous dragon tree[21] at Orotava, in the island of Teneriffe. Two other examples are known in California—the pseudo-cedar, or _Tascodium_, at Sacramento, and a _Sequoïa gigantea_. We know that the olive tree may live 700 years. There are cedars 800 years old and oaks of the age of 1,500 years. [21] Lately destroyed in a storm. [Tr.] _Plants with a Rhizome._—Vegetable species of almost unlimited duration of life are known to botanists. Such, for instance, are plants with a definite rhizome, such as colchicum. Autumnal colchicum has a subterranean root, the bulb of which pushes out every year fresh axes for a new bloom; and as each of these new axes stretches out an almost constant length, a botanist once set himself the singular problem of discovering how long it would take such a foot, if suitably directed, to travel round the world. _Vegetables Reproduced by Cuttings._—Vegetables reproduced by slips furnish another example of living beings of indefinite duration. The weeping willows which adorn the banks of sheets of water in the parks and gardens throughout the whole of Europe have sprung, directly or indirectly, from slips of the first _Salix Babylonica_ introduced to the West. May it not be said that they are the permanent fragments of that one and the same willow?