coat, and attached distinctly to their placenta. The rind was called Malicorium by Ruellius.

Fruit of which the principal characters are derived from the incrassated floral envelopes.

XXXII. DICLESIUM. — (Dyclesium, Desvaur; Scleranthum, Manch ; Cataclesium, Desvaux; Sacellus, Mirb.)

Pericarpium indehiscent, one-seeded, enclosed within an indurated perian

Pericarpium indehiscent, one-seeded, enclosed within a fleshy perianthium.
Examples. Hippophäe, Taxus, Blitum, Basella.

XXXIV. SYCONUS. (Syconus, Mirb.)

A fleshy rachis, having the form of a flattened disk, or of a hollow receptacle, with distinct flowers and dry pericarpia.

Examples. Ficus, Dorstenia, Ambora.

XXXV. STROBILUS, Cone (Conus, or Strobilus, Rich., Mirb.; Galbulus, Gartn.; Arcesthide, Desvaux; Cachrys, Fuchs; Pilula, Pliny), fig. 166.

An amentum, the carpella of which are scale-like, spread open, and bear naked seeds; sometimes the scales are thin, with little cohesion; but they often are woody, and cohere into a single tuberculated mass.

The Galbulus differs from the Strobilus only in being round, and having the heads of the carpella much enlarged. The fruit of the Juniper is a Galbulus, with fleshy coalescent carpella. Desvaux calls it Arcesthide. Example. Pinus.

XXXVI. SOROSIS. - (Sorosis, Mirb.)

A spike or raceme converted into a fleshy fruit by the cohesion in a single mass of the ovaria and floral envelopes.

Examples. Ananassa, Morus, Artocarpus.

As the fruit is the ovarium arrived at maturity, and is therefore subject to the same laws of structure as the latter; so is the seed the ovulum in its most perfect and finally organised state, and constructed upon exactly the same plan as the ovulum. But as the fruit, nevertheless, often differs from the ovarium in the suppression, or addition, or modification of certain portions, so is the seed occasionally altered from the precise structure of the ovulum, in consequence of changes of like nature.

The seed is a body enclosed in a pericarpium, is clothed with its own integuments, and contains the rudiment of a future plant. It is the point of developement at which vegetation stops, and beyond which no increase, in the same direction with itself, can take place. In a young state it has already been spoken of under the name of ovulum; to which I also refer for all that relates to the insertion of seeds.

That side of a seed which is most nearly parallel with the axis of a compound fruit, or the ventral suture or sutural line of a simple fruit, is called the face, and the opposite side the back. In a compound fruit with parietal placenta, the placenta is to be considered as the axis with respect to the seed; and that part of the seed which is most nearly parallel with the placenta, as the face. Where the raphe is visible, the

face is indicated by that.

When a seed is flattened lengthwise it is said to be com

pressed, when vertically it is depressed; a difference which it is of importance to bear in mind, although it is not always easy to ascertain it: for this purpose it is indispensable that the true base and apex of the seed should be clearly understood. The base of a seed is always that point by which it is attached to the placenta, and which receives the name of hilum; the base being found, it would seem easy to determine the apex, as a line raised perpendicularly upon the hilum, cutting the axis of the seed, ought to indicate the apex at the point where the line passes through the testa: but the apex so indicated would be the geometrical, not the natural apex; for discovering which with precision in all seeds, the natural and geometrical apex of which do not correspond, another plan must be followed. If the testa of a seed be carefully examined, it will usually be found that it is composed in great part of lines representing rows of cellular tissue, radiating from some one point towards the base, or, in other words, of lines running upwards from the hilum and meeting in some common point. This point of union or radiation is the true apex, which is not only often far removed from the geometrical apex, but is sometimes even in juxtaposition with the hilum, as in mignonette: in proportion, therefore, to the obliquity of the apex of the seed will be the curve of its axis, which is represented by a line passing through the whole mass of the seed from the base to the apex, accurately following its curve. If the lines above referred to are not easily distinguished, another indication of the apex resides in a little brown spot or areola, hereafter to be mentioned under the name of chalaza. Where there is no indication either externally or internally of the apex, it may then be determined geometrically.

The integuments of a seed are called the testa; the rudiment of a future plant, the embryo (Plate VI. fig. 1. b, &c.); and a substance interposed between the embryo and the testa, the albumen (fig. 1. a, 5. a, &c.).

The testa, called also lorica by Mirbel, perisperme and episperme by Richard, and spermodermis by De Candolle, according to some consists, like the pericarpium, of three. portions; viz. 1. the external integument, tunica externa of

Willdenow, testa of De Candolle; 2. the internal integument, tunica interna of Willdenow, endopleura of De Candolle, hilofere and tegmen of Mirbel; and, 3. of an intervening substance answering to the sarcocarpium, and called sarcodermis by De Candolle: this last is chiefly present in seeds with a succulent testa, and by many is considered a portion of the outer integument, which is the most accurate mode of understanding it.

The outer integument is either membranous, coriaceous, crustaceous, bony, spongy, fleshy, or woody; its surface is either smooth, polished, rough, or winged, and sometimes is furnished with hairs, as in the cotton and other plants, which, when long and collected about either extremity, form what is called the coma (sometimes also, but improperly, the pappus). It consists of cellular tissue disposed in rows, with or without bundles of vessels intermixed: in colour it is usually of a brown or similar hue: it is readily separated from the inner integument.

In Maurandya Barclayana it is formed of reticulated cellular tissue; in Collomia linearis and others it is caused by elastic spirally twisted fibres enveloped in mucus, and springing outwards when the mucus is dissolved; in Casuarina it (or the inner integument) contains a great quantity of spirally fibrous cellules. In the genus Crinum it is of a very fleshy, succulent character, and has been mistaken for albumen, from which it is readily known by its vascularity. According to Mr. Brown, a peculiarly anomalous kind of partition, which is found lying loose within the fruit of Banksia and Dryandra, without any adhesion either to the pericarpium or the seed, is a state of the outer integument. It is said that in those genera the inner membrane (secondine) of the ovulum before fertilisation is entirely exposed, the primine being dimidiate and open its whole length; and that the outer membranes (primines) of the two collateral ovula, although originally distinct, finally contract an adhesion by their corresponding surfaces, and together constitute the anomalous dissepiment. But it may be reasonably doubted whether the integument here called secondine is not primine, and the supposed primine arillus.

The inner membrane (secondine) of the ovulum, however, in general appears to be of greater importance as connected with fecundation, than as affording protection to the nucleus at a more advanced period. For in many cases, before impregnation, its perforated apex projects beyond the aperture of the testa, and in some plants puts on the appearance of an obtuse, or even dilated stigma; while in the ripe seed it is often either entirely obliterated, or exists only as a thin film, which might readily be mistaken for the epidermis of a third membrane, then frequently observable.

"This third coat (tercine) is formed by the proper membrane or cuticle of the nucleus, from whose substance in the unimpregnated ovulum it is never, I believe, separable, and at that period is very rarely visible. In the ripe seed it is distinguishable from the inner membrane only by its apex, which is never perforated, is generally acute and more deeply coloured, or even sphacelated.”

M. Mirbel has, however, justly remarked that the primine and the secondine are, in the seed, very frequently confounded; and that therefore the word testa is better employed, as one which expresses the outer integument of the seed without reference to its exact origin, which is practically of little importance. The tercine is also, no doubt, often absent. He observes, that these mixed integuments often give rise to new kinds of tissue; that in Phaseolus vulgaris the testa consists, indeed, of three distinct layers, but of those the innermost was the primine; and that the others, which represent nothing that pre-existed in the ovulum, have a horny consistence, and are formed of cylindrical cellules, which elongate in the direction from the centre to the circumference. And this is probably the structure of the testa of many Legu

minosa.

It sometimes happens that the endopleura (or tercine?) thickens so much as to have the appearance of albumen, as in Cathartocarpus fistula. In such a case as this it is only to be distinguished from albumen by gradual observation from the ovulum to the ripe seed.

With regard to the quartine and quintine, one of them is occasionally present in the form of a fleshy sac that is interposed between the albumen and the ovulum, and envelopes