The family of Coniferæ exhibit themselves in Australia, like every other group of plants, under strange and novel forms. The shape of those trees is generally fusiform and pyramidal; their leaves are sometimes extraordinarily small, sometimes large and flattened. Many are of great size; none, however, attaining the gigantic proportions of the celebrated columnar Pine of New Caledonia, which Cook's companions mistook for a colossal mass of basaltic pillars, and which Moore, like a true son of industrious Albion, compared to an enormous factory-chimney. This tree exceeds 160 feet in height, and its ramifications, all of the same height, radiate regularly around its trunk, from the base even to the summit. [Illustration: 1. Ravenala Madagascariensis. 2. Heritiera argentea. 3. Tanghin.] * * * * * [Illustration: A FOREST IN MADAGASCAR.] I have now to ask the reader's companionship on an excursion into the forests of the great African island of Madagascar. The insalubrity of the climate and the jealous inhospitality of the inhabitants will not permit us to penetrate far into their luxuriant depths; but the most superficial glance will satisfy us upon their wild magnificence and the original variety of their superb flora.[167] We should seek in vain among their leafy, blossoming glades, for the famous Manchineal, a member of the American _Euphorbiaceæ_, which holds a high place in the records of vegetable poisons; but the toxicological amateur will find ample compensation in examining the formidable Tanghin,[168] whose deadly juice, mixed with some other substances, plays an important part in the judicial ordeals popular among the Malagasy. The Tanghin, or Tanguen (_T. venenifera_), is the only plant of its genus, and is confined to Madagascar. It is described as a tree with smooth alternate leaves of moderate thickness, clustered towards the points of the branches, with large terminal cymes of flowers, having a salver-shaped corolla, with rose-coloured lobes. The ovary is twofold, with a long style and thick stigma; but usually only one attains to perfection, and forms an ellipsoid fruit, somewhat pointed at the ends, invested in a smooth purplish-green skin, and containing a hard stone surrounded by a thick fibrous pulp. The poisonous seed of the Tanghin is esteemed by the natives an infallible criterion of guilt or innocence. After being pounded, a small piece is swallowed by the supposed criminal. If he be cursed with a strong stomach, which retains the poison, he speedily dies, and is held guilty; if his feeble digestion rejects it, he necessarily escapes, and his innocence is considered proven.