ARBOR VITAE (Tree of Life), a name given by Clusius to species of Thuja. The name Thuja was adopted by Linnaeus from the Thuya of Tournefort and seems to be derived from the Greek word 6vos, signifying sacrifice, probably because the resin procured from the plant was used as incense. The plants belong to the family Coniferae, tribe Cupressineae (Cypresses). Thuja occidentalis is the Western or American arbor vitae, the Cupressus Arbor Vitae of old authors. It is a native of North America, and ranges from Canada to the mountains of Virginia and Carolina. It is a moderate-sized tree, and was introduced into Britain before 1597, when it was mentioned in Gerard's Herbal. In its native country it attains a height of about Soft. The leaves are small and imbricate, and are borne on flattened branches, which are apt to be mistaken for the leaves. When bruised the leaves give out an aromatic odour. The flowers appear early in spring, and the fruit is ripened about the end of September. In Britain the plant is a hardy evergreen, and can only be looked upon as a large shrub or low tree. It is often cut so as to form hedges in gardens. The wood is very durable and useful for out door work, such as fencing, posts, etc. Another species of arbor vitae is Thuja orientalis, known also as Biota orientalis. The latter generic name is derived from the Greek adjective i3iwrin, formed from (3Los, life, probably in connection with the name "tree of life." This is the Eastern or Chinese arbor vitae. It is a native of China. It was cultivated in the Chelsea Physic Garden in 1752, and was believed to have been sent to Europe by French missionaries. It has roundish cones, with numerous scales and wingless seeds. The leaves, which have a pungent aro matic odour, are said to yield a yellow dye. There are numerous varieties of this plant in cultivation, one of the most remarkable being pendula, with long, flexible, hanging, cord-like branches. The variety pygmaea forms a small bush a few inches high.