single, superior, coloured internally, and 3-4-5 cleft, with a valvate æstivation of the lobes. The stamina are definite, opposite the sepals, which they equal or double in number, and from the base of which they are exserted. The anthers are terminal and 2-celled, (rarely 4-celled.) The ovarium is generally inferior, 1-celled, with 1-2-4 pendulous ovules, springing from the top of a free central placenta. This style is single, and the stigma often lobed. The fruit is indehiscent, hard and dry, or sometimes slightly succulent, and by abortion monospermous. The seed is exarillate and pendulous, the albumen fleshy, and of the same shape as the seed, the embryo axile, and the radicle superior.

(1707.) Hence, with reference to the chief associating and differential characters alone, the Santalacea are albuminous exarillate Laurinæ, with a valvate æstivation of the calyx, and in general, inferior 1-celled ovaries and solitary seeds.

(1708.) The three subtypes Osyrida, Nyssida, and Santalida, exhibit a most interesting series of modifications occurring in plants closely allied to each other, and yet deviating from the rule of their association to establish connexions with surrounding groups.

Thus

(1709.) In the Osyride the ovarium is free and superior, the stamens 3 (?), and the perianth 3-cleft.

(1710.) In the Nysside the ovarium is inferior and the calyx adnate, the 1-celled ovary is 1-ovuled, and the flowers are polygamous, the embryo is not cylindrical, and the cotyledons are large and foliaceous.

(1711.) While in the Santalida the inferior 1-celled ovary is 3-ovuled, the fruit becoming 1-seeded by abortion, and the embryo is round.

(1712.) Osyridæ. The Osyris of Pliny, according to the accounts transmitted to us, was a marvellous vegetable, endowed with the property of curing every disease. The Poet's cassia, our modern Osyris, cannot certainly be the plant which he describes, for, excepting a slight astringency, it possesses no sensible properties as a medicine, and is now only used for making besoms, for which its long slender

supple branches fit it. 0. Japonica is occasionally eaten as a salad. Exocarpus has received its name from the enlarged receptacles on which the fruit is placed, giving it the appearance of being a seed outside of its seed-vessel: a new species of Exocarpus, discovered by Mr. Bauer, and mentioned by Dr. Brown, in the Appendix to Flinder's Voyage,' is remarkable for bearing its flowers on the margins of dilated foliaceous branches, concerning which it would be difficult otherwise to determine whether they were boughs or leaves.

(1713.) Nyssida. The Ogeehee Lime is the fruit of Nyssa candicans, and the fruits of other species are preserved by the French colonists on the Mississippi, and used instead of olives. The Nyssa are trees of great singularity and beauty, especially N. denticulata, which rises to the height of 80 or 100 feet. Its wood is white, soft, compact, and light, and therefore valued by the carver and turner.

(1714.) Santalida. The Thesia are inodorous, slightly astringent plants, of little beauty. The Theseion of the ancients was said to have been so named on account of its having been presented to Ariadne by Theseus, but our plant cannot be the one to which Athenæus and Timachides refer, as its obscure flowers, devoid of elegance, would scarcely have caused it to be selected for such a purpose. The Santala or sandal-woods, especially the Santalum album, or true sandal,

T

are peculiarly fragrant. Hence their timber is much valued. When young it forms the white sandal, and when old, the yellow sandal wood of commerce; and, so great is the demand for it, that the trees are seldom allowed to grow to more than a foot in diameter. It is made into musical instruments, cabinets, and curious boxes, for which it is valued, as no insect can exist, nor iron rust (it is said) within its influence. The oil used by the Brahmins in their religious ceremonies is scented with sandal, and with the dust of the wood they form the pigment which they use in giving the frontal mark to the god Vishnu. Sandal-wood is extensively employed at the funerals of the Hindoos, and the nearer it is got from the root, and the deeper the colour, the greater is the fragrance. It is an article of export from the Malabar coast to Bengal and China, but is seldom brought to Europe. The native doctors, in India, consider it to be possessed of sedative and cooling properties, and occasionally use it as a medicine.

(1715.) TERMINALIACEE. Terminalia, Bucida, and the other genera included in this type, were formerly associated with the Santalacea and Elæagnide of the Thymelaacea, under the common name Eleagneæ. But on the reformation of this Jussieuan group, by its author and succeeding botanists, the Terminaliacea were separated from the Eleagnide and Santalacea, and admitted as a distinct and separate type. Its connexions, however, are so numerous and so distant, that its systematic arrangement is a matter of difficulty; for so close are its affinities with Combretum and the other Combretacea, that the two groups have often been conjoined, and then the dichlamydeous flowers of the latter would lead to their joint location near the Onagrariacea, amongst the polypetalous Rosales. It seems therefore most advisable to leave the Terminaliaceæ, which are apetalous, in the neighbourhood of the Santalacea and Elæagnidæ, with which they "agree in many important particulars," and only to transfer the polypetalous Combretacea to the Onagrinæ of the Rosales: as this may perhaps fulfil the double indication to which De Candolle adverts, when he says they may be placed indifferently in the neighbourhood of the distant groups just mentioned, to one of which they are related by the apetalous, and to the other by the polypetalous genera.

(1716.) The Terminaliacea are tropical shrubs or trees, with alternate (rarely opposite), exstipulate, entire, coriaceous leaves. The inflorescence is in axillary or terminal spikes or racemes, the flowers are regular, united (rarely polygamous by abortion), the calyx adnate to the germen, the limb 5-lobed, valvate in æstivation, and deciduous. Petals none, stamens definite, arising from the orifice of the tube of the perianth, and in general double the number of its lobes: filaments free, anthers terminal, 2-celled, with opposite locules dehiscing by a longitudinal chink, germen inferior and 1-celled, ovules definite (2-4-5) and pendulous from the upper part of the ovary, but not attached to any central column. The style is single, and the stigma undivided.

The fruit is indehiscent, either dry or succulent, often ribbed or winged, 1-celled, and in general, by abortion, monospermous. The seed is large, pendulous, and exalbuminous, the embryo straight and cylindrical, the radicle turned towards the hilum, and the cotyledons spirally folded.

(1717.) Hence, differentially considered, the Terminaliacea are exalbuminous Laurinæ, with a superior calyx, the limb valvate in æstivation, and deciduous; an inferior 1-celled ovarium without any central column, definite pendulous ovules, and spiral cotyledons.

(1718.) The Terminaliaceæ are astringent plants. Terminalia vernix abounds with a resinous juice that is used in the Moluccas and in China as a varnish, and T. catappa affords a black pigment with which the Indians dye their cloth, and from which Indian pink is made. The fruits of Terminalia bellerica and T. chebula are very astringent, more especially the latter, which, as well as the galls with which it abounds, are used for tanning leather. The root of T. latifolia is administered medicinally in Jamaica in cases of diarrhoea, as is also the bark of T. alata. Bucida buceras, the black olive or French oak of the West Indies, yields excellent timber, and its bark is highly valued by the tanners, as is likewise that of Conocarpus racemosa, one of the plants called mangroves in the West Indies.

HIPPURINE.

(1719.) The plants included in this small section have, like the Terminaliaceæ, been in general referred to the polypetalous series, and associated like them with the Onagrina. Dr. Brown and others have, however, noticed the incongruity of this arrangement, and occasionally one or more of the types now brought together in this section have been transferred to the apetalous division.

(1720.) The HIPPURINE, collectively considered, are monochlamydeous Rosares, i. e. herbaceous or suffruticose Querneales, with or without albumen, and the cotyledons variable; being either very small, unequal, or numerous.

(1721.) Three types are included in this section, to which the normal genera Hippuris, Trapa, and Ceratophyllum, have given their names respectively.

(1722.) HIPPURIDACEE. (Halorageæ R. Br.) Haloragis (the sea-grape), Hippuris (the mare's-tail), and Callitriche (the water-starwort), which, together, form this type, are herbaceous aquatic plants, with whorled, opposite (or rarely alternate) leaves, without stipulæ.

The flowers are axillary or disposed in terminal spikes, united or separated, apetalous, and often with two fistular coloured bractea. The tube of the calyx is adherent to the ovary, and the limb obscure. The petals none, or very minute. The stamens 1-2, or more, perigynous. The anthers 1-2-celled, dehiscing longitudinally, and the connectivum obsolete. The germen is inferior, 1-4-celled, each cell 1-4-seeded. The fruit is dry and indehiscent, 1-4-celled, 1-4-seeded, the seeds pendulous, the albumen fleshy, the embryo straight and axile, the radicle superior and long, and the cotyledons two and small.

(1723.) Hence, differentially considered, the Hippuridacea are albuminous Hippurina, with inferior ovaries, and two equal minute cotyledons.

(1724.) Haloragis, Calitriche, Hippuris, and their allies, though agreeing in the above general characters, differ in so many minor particulars that they are distributed into three subtypes, the Haloragida, Callitrichide, and Hippurida.

(1725.) In the Haloragida, the limb of the calyx is evidently parted. The petals sometimes developed. The stamens always more than two (3-8.)

(1726.) In the Hippuride the limb of the calyx is small and entire. The petals always absent. The flowers are monandrous, the anthers bilocular, and the fruit 1-celled and 1-seeded.

(1727.) In the Callitrichide the flowers are invested by two petaloid bracteæ, the limb of the calyx is abortive, the stamens are sometimes (though rarely) two in number, the anthers unilocular, and the fruit 4-celled. Each cell being monospermous, and the seeds peltate.

(1728.) These plants do not possess any notable properties; they are innoxious, and perhaps slightly nutritious, as they are fed on by wild ducks; and, growing abundantly in damp places, are said, by the large quantities of carbonic acid and carburetted hydrogen they absorb, to tend much towards purifying the air of marshes, and rendering that in water respirable by fish and other aquatic animals. (1729.) TRAPACEE. The water-caltrops (Trapa), is typical of this group, sometimes called Hydrocaryes or water-nuts, in reference to the large eatable seeds which all the species produce. The word Trapa is an abridgment of Calcitrapa, the Latin name of an instrument of war, designed to impede the progress of cavalry, and to which the fruit of some of the Trapa, furnished with strong spines, bears a fanciful resemblance.

(1730.) The Trapacea are floating herbaceous plants, with the lower leaves capillary and opposite, the upper ones entire and alternate, and the petioles tumid in the middle. The inflorescence is axillary, the flowers small, the calyx superior and 4-parted, the petals developed equal in number to the lobes of the calyx, and exserted from its faux. The stamens 4, perigynous, and arising alternately with the petals. The ovary is 2-celled, and the ovule solitary and pendulous; the style is filiform, thickened at the base, and the stigma capitate. The fruit is dry, hard, and indehiscent, 1-celled, 1-seeded, and crowned by the indurated segments

of the calyx. The seed is large, pendent, solitary, and exalbuminous: and the embryo straight, with two very unequal cotyledons.

(1731.) Hence, differentially considered, the Trapacea are exalbuminous Rosares, with two very unequal cotyledons.

(1732.) From the exceeding disparity of the seed-lobes, the Trape were once considered to be monocotyledons, and associated with the Hydrocharina, and it is probable that they, as well as some other plants, already and hereafter to be mentioned, are intermediate stages between the two great schemes of structure evidenced in the di- and mono-cotyledons. Trapa natans is an European plant, abounding in Switzerland and the South of France. Some of the canals at Versailles are covered with it, and the fruit is collected and eaten as chesnuts. At Venice they are sold under the name of Jesuit's-nuts; at Vercelli they are called galarin, and are much eaten by the common people and children. Pliny tells us that the Thracians used to make them into bread. Trapa bicornis, which is common in China and Japan, is often brought to this country on account of its singular two-horned seeds, resembling the head of a bull. Thunberg says that in Japan these farinaceous nuts are put into broth or made into porridge. T. bispinosa, quadrispinosa, &c. are eaten in the countries where they grow; the former is much esteemed by the Hindoos.

(1733.) CERATOPHYLLACEE. Ceratophyllum, the horn-wort, of which but seven species have been discovered, stands alone in this type, the affinities of which have been much disputed, but which seems only with violence to be removed far from Trapa, Hippuris, and Myriophyllum.

(1734.) The Ceratophyllacea are much-branched floating herbs, with whorled, multifid, cellular, exstipulate leaves, the segments being filiform and subserrate.