chain of evidence which establishes the derivative origin of specific forms.
Prof. Gray thinks the age of the oldest living Sequoia may be about 2,000 years, and remarks: "It is probable that close to the heart of some of the living trees may be found the circle which records the year of our Saviour's nativity." Fig. 7 is a representation of the Sequoia.
The sacred banian, before noticed, is familiar to every reader. Its main trunk attains a diameter of from 20 to 30 feet, and its enormous roof of foliage may shelter the inhabitants of a considerable village. The pendent branches are really roots, which, on reaching the ground, penetrate it and form trunks. These correspond with the outer layers of wood in an oak or a pine, and sustain the top, although the original trunks decay and disappear.
The dragon-tree of Orotava, on the island of Teneriffe, is a well-known and historic tree. Our representation of it (Fig. 8) is from a drawing made in 1776. Twice during the present century it has been dismantled by storms. It is but 69 feet high, but is 79 feet in circumference. So slow is its growth that its diameter had scarcely changed in 400 years. Recently it bore flowers and luxuriant foliage, as it may have done before the "isles of the Western Ocean," on one of which it was growing, were a dream in the Grecian mythology.
The baobab, or monkey bread-fruit, is the last we can notice of the ancient trees. It was first described by a Venetian traveller in 1454. Fig. 9 is from a photograph of one on the west coast of Africa. These trees are found, however, in nearly all portions of that country south of the Desert, everywhere an imposing feature of the landscape, and objects of regard if not of reverence by the natives. In the rainy season they are in full luxuriance, and are covered with cup-shaped flowers six inches in diameter. The trunks grow from 20 to 60 feet high, but are sometimes 100 feet in circuit at the ground. The baobabs, like most other trees, grow rapidly when young, but slowly when old. Recent estimates attribute to some of the oldest a period of 3,000 years. This is scarcely more than one-half the age assigned to them by early writers.
In 1832 a baobab was transplanted into a garden at Caraccas, which grew as much in 40 years as would have required 100 years by early estimate. An account of this tree is published in Natur und Leben, No. 1, 1873.
By the native town of Shupanga, near the Zambesi, in Eastern Africa, is a venerable baobab, beneath which is the grave of Mrs. Livingstone.
Such, briefly, are some of the great living monuments of the vegetable kingdom. In longevity they are in striking contrast with higher types of life. Fixed to a single spot, the tree is what it is because of the forces which act upon it. It is a monument of accumulated and
