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ENDEAVOUR STRAIT. [Torres STRAIt] ENDE'CAGON, a figure of eleven sides. ENDECA'NDRIA, the ninth class of the Linnaean system of botany, distinguished by having nine stamens separate from each other. ENDEMIC (ovönuoc, endémus, from iv, in or among; and Čiuoc, people, that which is among a people). By this word are expressed those peculiar forms of disease which arise spontaneously, as it is termed, in a country or in particular localities, and which are ordinarily produced by the peculiar climate, soil, air, water, &c. Thus, ague is the endemic disease of marshy countries or localities; the swelled throat or bronchocele is endemic in the Alps, and the plica in Poland. The word bears pretty much the same signification in relation to the diseases of a country that the term indigenous does to its plants. It is used in contradistinction to epidemic. [EPIDEMIC. ENDIVE, or CICHORIUM ENDIVIA, the parent of all the varieties of garden endive, was introduced to Britain about the beginning of the seventeenth century from the northern provinces of China. It is a species belonging to the narcotic lactescent division of Compositae, to which it gives the name Cichoraceae. There are now many varieties in cultivation, which are divided, by those who have classed them, into two principal groups, Batavian and Curled-leaved; arranging under the former all those with broad ragged leaves, and under the latter those in which the leaves are narrower and curled. The French call the first of these Scaroles and the last Chicorées. As it is the leaves of this plant, and not its flowers or seed, which are used in culinary operations, it is necessary to be particular as to the time of sowing; for if sown early in spring, it will, instead of forming fine leaves, produce flowers and seed, and so frustrate the object of the cultivator. A little seed may be sown in the beginning of May for early use; but for a general crop, throughout, the months of June, July, to the middle of August, will be found to be the proper time for sowing. The soil upon which the endive is sown or planted should be light and r:ch. After the plants are strong enough to be removed from the seed-bed and planted out where they are intended to remain, various methods are practised in order to blanch the leaves. Some gardeners plant in drills two or three inches deep, and earth up the plants as they grow; others, after they are fully grown, cover them with flower-pots, or something of that description, and so exclude the light; while others again simply tie the leaves close together with a piece of matting, when the same result is obtained. The effect of thus blanching the plants is not merely to render the endive colourless when employed as salad, but to diminish its natural bitterness, which in its concentrated state would render it unfit for food. Endive-plants are impatient of wet in cold weather, being apt to rot in open situations. Care, therefore, should be taken to protect them by mats or boards upon the approach of winter. In this country the cut-leaved or ‘curled’ endive is preferred for table; but the dwarf white Batavian endive is much more delicate and agreeable to the palate. E'NDOGENS. One of the large primary classes into which the vegetable kingdom is divided bears this name in consequence of its new woody matter being constantly developed in the first instance towards the interior of the trunk, only curving outwards in its subsequent course downwards. That palm-trees grow in this way was known so long since as the time of Theophrastus, who distinctly speaks of the differences between endogenous and exogenous wood. But that this peculiarity is also extended to a considerable part of the vegetable kingdom is a modern fact, the discovery of which we owe to the French naturalists Daubenton and Desfontaines. The path being thus opened, the inquiry has . and more particularly of late years, been much extended, especially by Professor Mohl, in an elaborate essay upon the anatomy of palms. In the following observations we shall be found to differ in some respects from all the previous writers upon this subject, but at the same time a considerable part of our statements will necessarily be in accordance with those of one observer or another. We do not think it advisable, except here and there, to interrupt the thread of our argument by any references to these discrepancies; the reader learned in

E N D such matters will be able to separate the views that are new from such as have previously been promulgated: others would be little interested in the matter. Mohl is of opinion that the first year's wood of an exogen is analogous in arrangement to that of an endogen, the woody bundles of each leaf curving upwards and outwards to the base of the leaf, and downwards and outwards towards the bark, crossing through those which have been previously developed. For convenience we will take the phaenomena of growth in a palm-tree as typical of the endogenous structure. In the beginning the embryo of a palm consists of a cellular basis, in which a certain number of cords of ligneous fibre are arranged circularly (fig. A, p. 396), down the radiele, deriving their origin from the plumule. Immediately subsequent to germination, and as soon as the rudimentary leaves of the plumule begin to o spiral vessels appear in their tissue in connection with the ligneous cords; the latter increase in quantity as the plant advances in growth, shootin downwards though the cellular tissue, and keeping paralle with the outside of the root. At the same time the cellular tissue increases in diameter to make room for the descending ligneous cords (or woody bundles, as they are also called). At last a young leaf is developed with a considerable number of such cords proceeding from its base downwards, and, as its base passes all round the plumule, consequently passing downwards alike on all sides of the centre that it surrounds. Within this a second leaf gradually unfolds, the cellular tissue increasing horizontally at the same time; the ligneous cords, however, soon cease to maintain any thing like a parallel direction, but curve outwards as they pass downwards, losing their extremities in the roots, or in the cellular integument on the outside of the first circle of cords (fig. A); at the same time the second leaf pushes the first leaf a little from the centre towards the circumference of the plane or cone of growth; tho consequence of which is that the ligneous cords next the base of the first leaf are drawn a little outwards, and form descending axes which henceforwards are found at first to curve inwards towards the centre of the young stem, and afterwards outwards towards its circumference. In this manner leaf after leaf is developed, the horizontal cellular system enlarging all the time, and every successive leaf, as it forms at the growing point, emitting more woody bundles curving downwards and outwards, and consequently intersecting the older arcs at some place or other; the result of this is that the first formed leaf will have the upper end of the arcs which belong to it longest and much stretched outwardly, while the youngest will have the arcs the straightest; and the appearance produced in the stem will be that of a confused entanglement of woody bundles in the midst of a quantity of cellular tissue. As the stem extends its cellular tissue longitudinally while this is going on, the woody arcs are consequently in proportion long, and in fact usually appear to the eye as if almost parallel, excepting here and there, where two arcs abruptly intersect each other. As in all cases the greater number of arcs curve outwards as they descend, and eventually break up their ends into a multitude of fine divisions next the circum ference, where they form a cortical integument, it will follow that the greater part of the woody matter of the stem will be collected near the sicumference, while the centre is kept comparatively open, and will consist chiefly of cellular tissue; and when, as in many palms, the stem has a limited circumference, beyond which it is its specific nature not to distend, the density of the circumference must, it is obvious, be proportionably augmented. It is however a mistake to suppose that the great hardness of the circumference of old palm wood is owing merely to the presence of augmenting matter upon a fixed circumference; this will account but little for the phenomena. We find that the woody bundles next the circumference are larger and harder than they originally were, and consequently we must suppose that they have the power of increasing their own diameter subsequent to their first formation, and that they also act as reservoirs of secretions of a hard and solid nature, after the manner of the heartwood of exogens. . . When the growth of the stem of an endogen goes on in this regular manner, with no power of extending horizontally beyond a specifically limited diameter, a stem is formed, the transverse section of which presents the appearance shown in the following cut. There is a number of curved spots crowded o in a 3 E 2

confused way, most thick and numerous at the circumference, comparatively small and o placed at the centre; and the only regular structure that is observable with the naked eye is that the curves always present their convexity to the circumference. When there is no limited circumference assigned by nature to an endogen, then the curved spots, which are sections of the woody arcs, are much more equally arranged, and are less crowded at the circumference. Never is there any distinct column of pith, or medullary rays, or concentric arrangement of the woody arcs; nor does the cortical integument of the surface of endogenous stems assume the character of bark, separating from the wood below it; on the contrary, as the cortical integument consists very much of the finely divided extremities of the woody arcs, they necessarily hold it fast to the wood, of which they are themselves prolongations, and the cortical integument can only be stripped off by tearing it away from the whole surface of the wood, from which it does not separate without leaving myriads of little broken threads behind. We therefore do not understand Professor Mohl when he asserts that the young wood of an exogen is the same as that of an endogen, and that they principally differ in exogens forming new wood between the old wood and liber, while endogens produce separate cords of woody tissue. On the contrary, exogens are, from the beginning of their growth, extremely different, collecting their woody cords in a parallel manner between those horizontal prolongations of the cellular system called medullary rays; there are no arcs developed; the cortical integument is altogether separate from the woody system, without any breaking off of the woody tubes; and, finally, there is a distinct column of cellular medulla, around which the wood itself is more or less concentrically disposed. We know very well that the disposition to form woody arcs in the pith, in addition to the concentric wood, which is so very conspicuous in Zamia, is also found elsewhere, as in Piper; and that something like it, although far from being correctly understood by Schultz, occurs in the pith of certain nyctaginaceous plants, as well as in elder, where it has been noticed by Henslow; but these cases are far from showing anything like identity between endogens and exogens, as will be more particularly explained in another place. [ExoGENs.] While however we object to Mohl's identification of exogens and endogens, as most forced and unnatural, and essentially at variance with observation, we are far from adopting the language of Link, who calls a palm stem a cauloma, as if it were not a stem at all. That there is in the stem of an endogen and an exogen the same elementary matter, that the woody bundles of the former are analogous to the woody plates of the latter, that the function of their stems, although not made out with much precision, is nevertheless essentially similar, are facts about which we cannot anticipate any dispute, and therefore the new term cauloma, as distinguished from caulis, is just as superfluous as the old name of frond as distinguished from leaf. In many of the larger kinds of endogens the stem increases principally by the development of a single terminal bud, a circumstance unknown in exogens, properly so called. In many however, as all grasses, the ordinary growth takes place by the full development of axillary buds in abundance. In general there is so great a uniformity in the structure of an endogenous stem that the common cane or asparagus illustrate its peculiarities sufficiently. There are however anomalous states that require explanation. Grasses are endogens with hollow stems strengthened by transverse plates at the nodes. This is seen in the bamboo,

whose joints are used as cases to hold rolls, or in any of our indigenous species. In this case the deviation from habitual structure is owing to the circumference growing faster than the centre, in. consequence of which is the tearing the latter into a fistular passage, except at the nodes, where the arcs of ligneous tissue originating in the leaves cross over from one side of the stem to the other, and by their entanglement and extensibility prevent the possibility of any rupture taking place. That this is so is proved by the fact that the stems of all grasses are solid, or nearly so, as long as they grow slowly; and that it is when the rapidity of their development is much accelerated that they assume their habitual fistular character. Independently of that circumstance their organization is quite normal. Xanthorhata hastilis has been shown by De Candolle to have an anomalous aspect. When cut through transversely, the section exhibits an appearance of medullary rays proceeding with considerable regularity from near the centre to the very circumference. (Organographie Végétale, t. 7.) But such horizontal rays are not constructed of muriform cellular tissue like real medullary processes, but are composed of ligneous cords lying across the other woody tissue; they are in fact the upper ends of the woody arcs pulled from a vertical into a horizontal direction by the growth of the stem and the thrusting of the leaves to which they belong from the centre to the circumference. Such a case throws great light upon the real nature of the more regular forms of endogenous wood. Other appearances are owing to imperfect development, as in some of the aquatic species of this class. Lemna, for example, has its stem and leaves fused together into a small lenticular cavernous body; and in Zannichellia and others, a few tubes of lengthened cellular tissue constitute almost all the axis; but the examination of such cases is comparatively unimportant, and would lead too much into details of subordinate interest. By far the most striking kind of anomaly in the stem of endogens is that which occurs in Barbacenia, and which has been already slightly noticed by the writer of this sketch. (Nat. Syst, of #o. p. 334.) It is so very important that we shall describe it more particularly on this occasion. In an unpublished species of Barbacenia from

Rio Janeiro, allied to B. pilrpūrea, the stems appear externally like those of any other rough-barked lo. onl that their surface is unusually fibrous and ragged when old, and closely coated by the remains of sheathing leaves when young. Upon examining a transverse section of it, the stem is found to consist of a small firm pale central circle having the ordinary endogenous organization, and of a large number of smaller and very irregular oval spaces pressed closely together but having no organic connection; between these are traces of a chaffy ragged kind of tissue which seems as if principally absorbed and destroyed. (See fig. A.) "A vertical section of the thickest part of this stem exhibits, in addition to a pale central endogenous column, woody bundles crossing each other or lying parallel, after the manner of the ordinary ligneous tissue of a Palm stem (fig. B), only the bundles do not adhere to each other, and are not embodied as usual in a cellular substance. These bundles may be readily traced to the central column, particularly in the younger branches (fig. C), and are plainly the roots of the stem, of exactly the same nature as those aërial roots which serve to stay the stem of a screw pine (Pandanus). When they reach the earth the woody bundles become more apparently roots, dividing at their points into fine segments, and entirely resembling on a small scale the roots of a palm-tree. The central column is much smaller at the base of the stem than near the upper extremity. Nothing can well show more distinctly than this, that the woody bundles of an endogenous stem are a sort of root emitted by the leaves, plunging down through their whole length into the cellular substance of the stem in ordinary cases; but in barbacemia soon quitting the stem and continuing their course downwards on the outside. The observation of Du Petit Thouars, that when dracaenas push forth branches, each of the latter produces from its base a quantity


of fibres, which are interposed between the cortical integu ment and the body of the wood, forming a sort of plaster analogous to what is found in the grast of an exogen; and that of the fibres just mentioned the lowermost have a tendency to descend, while those originating on the upper side of the branch turn downwards and finally descend also; that observation had already rendered the above-mentioned conclusion probable. The case of barbacenia can scarcely leave a doubt upon the subject, and leads to the imo conclusion that the theory of the wood of exogens eing also a state of roots belonging to the leaves of the stem, is well founded also. The age of endogenous trees has been little studied. When the circumference of their stem is limited specifically, it is obvious that their lives will be limited also; and hence we find the longevity of palms inconsiderable when compared with that of exogenous trees. Two or three hundred years are estimated to form the extreme extent of life in a date palm and in many others. But where, as in Dracaena, the degree to which the stem will grow in diameter is indefinite, the age seems, as in exogens, to be indefinite also thus a famous dragon tree, Dracaena Draco, of Oratava in Teneriffe, was an object of great antiquity so long ago as A. D. 1402, and is still alive. Important as the character furnished by the interna? manner of growth of an endogen obviously is, it is much enhanced in value by its being found very generally accomanied by peculiarities of organization in other parts. The eaves have in almost all cases the veins placed in parallel lines, merely connected by transverse single or nearly single bars. Straight-veined foliage is therefore an external symptom of an endogenous mode of growth. When such an appearance is found in exogens it is always fallacious, and is found to be owing to the excessive size and peculiar direction of a few of the larger veins, and not to be a general character of all the venous system; as is sufficiently obvious in Plantago lanceolata, Gentiana lutea, and many more. The flourers too of endogens have in most cases their sepals, petals, and stamens corresponding with the number three, or clearly referrible to that type; and the pistil usually participates in the same peculiarity. Where such a proportion exists in exogens, it is usually confined to the sepals and petals by themselves, or to the pistil by itself, not extending to the other organs. . In endogens it is almost universal in all the whorls of the flower, although sometimes obscured by the abortion, dislocation, or cohesion of particular parts, as happens in the whole of the extensive natural order of grasses. The effect of the manner of growth in endogens is to give them a very peculiar appearance. ... Their trunks frequently resemble columns rising majestically with a plume of leaves upon their summit; and the leaves, often very large—the fan-shaped leaves of some palms are from 20 to 30 feet wide—have most commonly a lengthened form, resembling a sword blade if stiff, or a strap if weak and broad. A landscape consisting entirely of endogens would have such an appearance as is presented by the cut in the preceding page. These peculiarities are connected with others belonging to endogenous vegetation in its most rudimentary condition. The embryo of an endogen is, in its commonest state, a small undivided cylinder, which protrudes from within its substance a radicle from one .." and a plumule from a little above the radicle; in other cases its embryo has a slit on one side, in the cavity of which the plumule reposes, or, finally, the embryo is a flat plate as in grasses, with the plumule and radicle attached to its face near the base. In the latter case the flat plate is a solitary cotyledon, which, in the second instance, is folded to: So as to give the embryo the appearance of being slit, and which in the first, or most habitual, condition is not only folded up, but united at its edges into a case entirely burying the umule and cotyledon. Hence the embryo of an endogen is called monocotyledonous; a name that is really unexceptionable, notwithstanding the occasional appearance of a second rudimentary cotyledon, as occurs in common wheat. It has already been stated that the radicle is protruded in germination from within the substance of the embryo ; the base of the radicle is consequently surrounded by a minute collar formed of the edges of the aperture produced by the radicle upon its egress. For this reason exogens are called endorhizal. Hence the great natural class of plants forming the subject of these remarks has five most important physiological peculiarities, by all which combined, or usually by each of which separately, the class may be characterized. 1. The wood is endogenous. 2. The leaves are straight-veined. 3. The organs of fructification are termary 4. The embryo is monocotyledonous. 5. The germination is endorhizal. This explains why Endogens are also called Monocoty. ledons and Endorhizae, they have moreover been called Cryptocotyledoneae by Agardh, Acroblasta by Reichenbach, and Caulophytae by the school of Oken; but these names have been given upon mere hypothetical grounds, and are not of sufficient importance to deserve explanation in this place. It may however be readily supposed that, viewed as a large class of plants, Endogens are essentially characterized only by the combination of these five peculiarities, and that occasional deviations may occur from every one of them. Thus in Nais, Caulinia, Zannichellia, and others which constitute a part of what Professor Schultz names Homorgamous floriferous plants, the whole organization of the stem is so imperfect that the endogenous character is lost; but their true nature is nevertheless sufficiently indicated by their straight veins, monocotyledonous embryo, &c. Again, in Smilax, the common reticulated leaves of exogens are found; but the endogenous stem, the ternary organs of fructification, the embryo and germination of that . , are all good evidence of its real nature; and so with other cases. Such occurrences are instances of endogenous development tending towards the exogenous, and are usually looked upon as cases of transition from one form to the other— |. not very correctly. Of this nature are the resemlangos between the columnar Cycadaceous Gymnosperms and Palms, between the livid, footid, one-sided calyx of Aris


i almaceae, consisting of Cocos capitata (a); Manicaria saccifera (b); Iriortea ventricosa (f). Pindanaceae, rc resented by Pandanus odoratissimus (c); Mw. sacca by Musa Sapientum (d); oraminace.e. by Bambusa arendinacea (e); and arborescent Amaryllidaceae, by Agave Americana (9). The fore and back

grounds are composed of smasl palms, grasses, rushes, and liliaceous plants,


tolochia and the equally livid, footid, one-sided spathe of araceous endogens, or, in another point of view, between such lenticular plants, as lemna in endogens, with the leaves and stems fused, as it were, together, and similar forms of stem and leaf among marchantiaceous acrogens.

With regard to really intermediate forms of vegetation connecting endogens with other classes, they are extremely uncommon. One of the most striking is that which occurs between Ranunculaceae and Nymphaeaceae on the part of exogens, and Alismaceae and Hydrocharaceae on that of endogens; if Ranunculus lingua, or better R. parnassifolius, is contrasted with Alisma plantago, or Damasonium, leaving out of consideration subordinate differences, it will be found that there is little of a positive nature to distinguish them except the albuminous dicotyledonous seeds of the former as compared with the exalbuminous monocotyledonous seeds of the latter; and the resemblances between Hydropeltis and Hydrocharis in the other case, are so very great that Schultz and others actually refer them to the same class.

Endogens probably contain more plants contributing to the food of man, and fewer poisonous species in proportion to their whole number, than exogens. Grasses, with their floury albumen, form a large portion of this class, to which have to be added Palms yielding fruit, wine, sugar, sago, Araceae, Marantaceae, some Amaryllidaceae, &c., producing arrow-root, the nutritious fruit of the plantains, the aro. matic secretions of Zingiberaceae, Orchidaceae forming salep, and Dioscoreaceae, the mothers of yams. Among the deleterious species we have little worth notice beyond the poisonous mucilage in the bulbs of certain Amaryllidaceae, and the acrid secretions of Araceae.

What proportion endogens bear to the whole vegetable kingdom is unknown. De Candolle computes the proportions of the three great classes into which plants used to be divided, thus:

Exogens, or Dicotyledons - - 636 Endogens, or Monocotyledons - 144 Acrogens, or Acotyledons - 220


But these numbers can only be regarded as loose approximations to the truth.

In these, as in all other large groups, we find the extremes of development so exceedingly far apart, that one would be almost tempted to doubt the possibility of their being mere forms of each other, were it not certain that numerous traces exist in the vegetable kingdom of a frequent tendency to produce the typical structure of a natural association of whatever kind in both an ea aggerated and degraded state, if such figurative terms may be employed in science. For instance, the genus Ficus contains some species creeping on the ground like diminutive herbaceous plants, and others rising into the air to the height of 150 feet, overspreading with the arms of their colossal trunks a sufficient space of ground to protect a multitude of men; the type of organization in the willow is in like manner represented on the one hand by the tiny Salir herbacea, which can hardly raise its head above the dwarf moss and saxifrages that surround it; and on the other by Salir alba, a tree sixty feet high. Then among natural orders we have the Rosaceous structure, exaggerated, on the one hand, into the arborescent Pomeae, and degraded, on the other, into the apetalous imperfect Sanguisorbeae; the Onagraceous type, highly developed in Fuchsia, and almost, obliterated in Halorageae; the Urticaceous, in excess in Artocarpus, and most imperfect in Ceratophyllum; grasses, presenting the most striking differences of perfection between the moss-like Knappia, and Bamboos a hundred feet high; and the Liliaceous occurs in ...} different states of development, when asparagus is compared with the Dragon-tree, or an autumnal squill with an arborescent Yucca. So, in like manner, we find at one extreme of the organization of the class of Endogens, palms, plantains, and arborescent liliaceous plants, and at the other, such submersed plants as Potamogeton, Zannichellia, and duckweed, the latter of which has not even the distinction of leaf and stem, and bears its flowers, reduced to one carpel and two stamens, without either calyx or corolla—therefore at the minimum of reduction, if to remain flowers at all—in little chinks in its edges.

The classification of endogens is not a subject upon which there is any very great diversity of opinion among botanists; if the natural orders are sometimes not distinctly limited, they are, upon the whole, grouped much better than those of exogens; and although it may be expected, whenever more positive rules for classification than are yet known shall have been discovered, that great changes will be introduced into this part of systematic botany, yet we do not contemplate the probability of disturbing the limits of the natural orders themselves to any considerable Cxtent. According to the views of the writer of this article (Nat. Syst. of Botany, ed. 2, p. 320, &c.), there are six principal groups into which endogens may be divided. Of these, four have the organization of the flowers perfect, there being in all cases a distinct calyx and corolla, and a regular consolidated cotyledon; and two are imperfect, the calyx and corolla being either altogether absent or in an incomplete condition, as in Araceae, where scale-like bodies are all that represent the floral envelopes, or grasses, in which for calyx and corolla are substituted imbricated scales, and the cotyledon is very commonly rolled up without consolidation or actually flat. The perfect groups consist, firstly, of plants whose leaves are those of exogens, having reticulated veins, a taper footstalk disarticulating from the stem, and the habit of Menispermaceae or Aristolochiaceae: these form the Retose group ; secondly, of straight-veined plants, some of which have a superior and others an inferior ovary: all those with a superior ovary form the Hypogynous group. Those with an inferior ovary separate into two series, of which one has a distinct style and stamens (Epigynosae), and the other those parts consolidated into a central column (Gynandrosae). The two groups of imperfect endogens are the Spadicose, in which a coloured spatha is usually present, and the flowers either altogether naked or provided only with rudimentary scales: in these plants the cotyledon is rolled up, but its edges are not united, so that it appears to have a slit on one side; and the Glumose, where the flowers have imbricated scales representing the calyx, and frequently minute scales in lieu of a corolla; in these the cotyledon is very usually flat, with the double cone, formed by the plumule and the radicle, adhering to its face at the lower end. The following table presents this arrangement in one view, and shows under which of the groups the different natural orders are stationed. Of all the more important of the latter, some account will be found in this Cyclopaedia at the proper places. ENDoGENs. * Perfect. Flowers complete. (Cotyledon usually rolled up and consolidated over the plumule and radicle. Group 1. EPIGYNous. Zingiberaceae, Marantaceae, Musaceae, Amaryllidaceae, Haemodoraceae, Burmanniaceae, Taccaceae, Iridaceae, Bromeliaceae, Hydrocharaceae. Group 2. GYNANDRous. Orchidaceae, Vanillaceae, Apostasiaceae. Group 3. Hypogynous. Palmaceae, Pontederaceae, Melanthaceae, Gilliesiaceae, Liliaceae, Commelinaceae, Butomaceae, Alismaceae, Juncaceae, Philydraceae. Group 4. RETose. Smilaceae, Dioscoreaceae, Roxburghlaceae. * * Imperfect. Flowers incomplete. (Cotyledon not consolidated, frequently quite flat and open.) Group 5. SPADIcose. Pandanaceae, Cyclanthaceae, Araceae, Acoraceae, Typhaceae, Naiadaceae, Juncaginaceae, Pistiaceae. Group 6. GLUMose. Graminaceae, Cyperaceae, Desvauxiaceae, Restiaceae (Eriocauleac), Xyridaceae.


ENDOSMOSE is the attraction through an animal or vegetable membrane of thin fluid by a denser fluid. Mons. Dutrochet found that if he filled the swimming bladder of a carp with thin mucilage and placed it in water, the bladder gained weight by attracting water through its sides: to this phenomenon he gave the name of Endosmose. He also found that if he filled the same bladder with water and placed it in thin mucilage, it lost weight, its contents being partially attracted through its sides into the surrounding mucilage; this counter phenomenon he named Earosmose. The same circumstances were seen to occur in the transmission of fluids through the tissue of plants; it was found possible to gorge parts of vegetables with fluid by merely placing them in water, and to empty them again by rendering the fluid in which they were placed more dense than that which they contained. It was also ascertained that this phenomenon took place with considerable force: Dutrochet says that water thickened with sugar in the pro

portion of 1 sugar to 2 water, was productive of a power of endosmose capable of sustaining a column of mercury of 127 inches, or the weight of 44 atmospheres. This phaenomenon is by its discoverer considered sufficient to explain many of the movements of the fluids both of plants, and animals; , his first book upon the subject is entitled L’Agent immédiat du Mouvement Vital, dooisé dans sa nature et dans son mode d'action chez les Végétaur et chez les Animaua, Paris, 1826, and in his numerous more recent writings he sustains the same opinion. To the effects of endosmose he refers the motion of sap; the sleep of leaves; the various directions taken by plants under the influence of external agents, such as turning to the light or away from it; many kinds of irritability; the attraction of fluids to particular points, and the like. That Mons. Dutrochet's arguments are extremely ingenious, and his observations highly curious, no one will deny; but we quite agree with De Candolle, that, supposing this celebrated physiologist's views to be correct, we must still have recourse to vital force as the great and inexplicable cause of all such phaenomena. When organic tissue dies, it does not lose its mere hygrometrical powers, nor do its tubes cease their capillarity, but no more vital movement of fluids takes place; yet mere endosmose will take effect through dead membranes, as is proved by the instrument called an endosmometer. We can only then allow endosmose to be one of the powers which, in combination with vital force, assists in producing some of the phenomena of life. Dutrochet considers endosmose to be owing to what he calls intercapillary electricity, grounding his opinion partly upon the experiment of Porret, who found that when two liquids of different levels are separated by a membrane, they may be brought to a level by establishing an electrical current between the two, thus rendering the membrane §. and partly upon experiments of his own. But I. Poisson, on the contrary, has demonstrated that endos mose may be the result of capillary attraction joined to differences in the affinity of heterogeneous substances. (Ann. de Chim., 1827, v. 35, p. 98.) ENEMATA. [ClystERs.] ENFEOFFMENT. [FEof FMENT.] ENFIELD, WILLIAM, was born at Sudbury, in Suffolk, on March 29, 1741, of humble but truly respectable parents. The disadvantages of his early education, arising from the condition of life in which he was born, were made amends for, in a great degree, by a fondness for reading and incessant labour towards improving his mind. This disposition to literary application introduced him to the notice of Mr. Hextall, the dissenting minister of the place, who kindly and judiciously directed him in his studies. Mr. Hextall's encouragement and advice led to his devoting himself to the Christian ministry. In his seventeenth year he was admitted to the Academy or Dissenting College at Daventry, then conducted by the Rev. Dr. Ashworth. Here he passed through the usual course of study of five years, and was distinguished for his habitual diligence and for an unusual facility and elegance of composition. It was here also that he, with some others of his fellow-students, were among the first of the dissenting ministry who formed the design of making Christian morality the Fo'. object of their discourses, rather than points of faith or the dogmas of sectarianism. Immediately on leaving the Academy, he was invited to the office of minister to the congregation of Benn's Garden, in Liverpool. In 1767 he married Mary, the only daughter of Mr. Holland, draper in Liverpool; a connexion which constituted his principal happiness for the rest of his life. In 1768 and 1770 he published two volumes of sermons, which were very favourably received. One of these volumes, now scarce, is rather remarkable for being embellished with vignette sketches illustrative of the subject of each discourse, from the pencil of Fuseli. He took his leave of Liverpool on being invited to the office of tutor in the belles lettres and resident conductor of the discipline at the academy of Warrington. . These offices he accepted in conjunction with that of minister, to the dissenting congregation of Warrington. . Of Dr; onfield's qualifications for the office of tutor in the belles lettres there could be no doubt; but if, as was supposed, his mild disposition and amiable manners disqualified him for a disciplinarian, it must in justice be acknowledged that sterner deportment and stricter discipline have also failed in preserving dissenting academical institutions from the

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