332 THE POPULAR SCIENCE MONTHLY. 



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 o\iter 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 circum- 

 ference. 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 gi-owing, 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. Liv- 

 ingstone. 



Such, briefly, are some of the great living monuments of the vege- 

 table 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 



