Page:EB1911 - Volume 21.djvu/759

From Wikisource
Jump to navigation Jump to search
This page has been proofread, but needs to be validated.
728
PLANTS
[CLASSIFICATION

was planned by him in those years—the publication of a Biblia polyglotta, which should fix the original text of Old and New Testaments on a scientific basis. In spite of clerical opposition he was supported by Philip II. king of Spain, who sent him the learned Benedictus Arias Montanus to take the leading part in the work of editorship. With his zealous help the work was finished in five years (1569-1573, 8 vols. folio). Plantin earned little profit, but received the privilege of printing all liturgical books for the states of King Philip, and the office of “prototypographus regius.” Though outwardly a faithful son of the church, he was till his death the partisan of a mystical sect of heretics; and it is now proved that many of their books published without the name of a printer came from his presses together with the missals, breviaries, &c., for the Roman Catholic Church.

Besides the polyglot Bible, Plantin published in those years many other works of note, such as editions of St Augustine and St Jerome, the botanical works of Dodonaeus, Clusius and Lobelius, the description of the Netherlands by Guicciardini, &c. In 1575 his printing-office reckoned more than twenty presses and seventy-three workmen, besides a similar number that worked for the office at home. But in November 1576 the town was plundered and in part burnt by the Spaniards, and Plantin had to pay an exorbitant ransom. He established a branch of his office in Paris; and when in 1583 the states of Holland sought a typographer for the newly erected university at Leiden, he left his much reduced business in Antwerp to his sons-in-law John Moerentorf (Moretus) and Francis van Ravelinghen (Raphelengius), and settled there. When in 1585 Antwerp was taken by the prince of Parma and affairs became there more settled, he left the office in Leiden to Raphelengius and returned to Antwerp, where he laboured till his death on the 1st of July 1589. His son-in-law, John Moretus, and his descendants continued to print many works of note “in officina Plantiniana,” but from the second half of the 17th century the house began to decline. It continued, however, in the possession of the Moretus family, which religiously left everything in the office untouched, and when in 1876 the town of Antwerp acquired the old buildings with all their contents, for 1,200,000 francs, the authorities were able with little trouble to create one of the most remarkable museums in existence (the Musée Plantin, opened August 19, 1877).

See Max Rooses, Christophe Plantin inprimeur anversois (Antwerp, 1882); Aug. de Backer and Ch. Ruelens, Annales de l'imprimerse Plantinienne (Brussels, 1865); Degeorge, La Maison Plantin (2nd ed., Brussels, 1878).

PLANTS. In the most generally used sense, a plant is a member of the lower or vegetable order of living organized things; the term is also popularly applied to the smaller herbaceous plants, thus excluding trees and shrubs. The early use of the word is for a twig, shoot, cutting or sapling, which was the meaning of Lat. planta (for plancta, the root being that seen in planus, flat, cf. Gr. πλατύς, broad; planta thus meant a spreading shoot or sucker). Other meanings of “plant” are derived from the verb “to plant” (Lat. plantare, to fix in position or place). It is thus used of the fixtures, machinery, apparatus necessary for the carrying on of an industry or business, and in colloquial or slang use, of a swindle, a carefully arranged plot or trap laid or fixed to deceive; cf. also Plantation. In the following sections the botanical sense of the word is followed, the term being used generally as opposed to “animals.”

Classification of Plants

Some account of the history of plant classification and the development of a natural system in which an attempt is made to show the actual relationships of plants, is given in the article Botany. The plant world falls into two great divisions, the higher or flowering plants (Phanerogams), characterized by the formation of a seed, and the lower or flowerless plants (Cryptogams), in which no seed is formed but the plants are disseminated by means of unicellular bodies termed spores. The term Cryptogam is archaic, implying a hidden method of reproduction as compared with the obvious method represented by the flower of the Phanerogam; with the aid of a good microscope it is, however, easier to follow the process of fertilization in many Cryptogams than in the flowering plants. These two great divisions are moreover of unequal value, for the Cryptogams comprise several groups differing from each other by characters as marked as those which separate some of them from the Phanerogams. The following groups or sub-kingdoms are those which are now generally recognized:—

Cryptogams I.  Thallophyta.
II.  Bryophyta.
III.  Pteridophyta.
Phanerogams  or IV.  Spermatophyta.

Thallophyta, are the most lowly organized plants and include a great variety of forms, the vegetative portion of which consists of a single cell or a number of cells forming a more or less branched thallus. They are characterized by the absence of that differentiation of the body into root, stem and leaf which is so marked a feature in the higher plants, and by the simplicity of their internal structure. Both sexual and asexual reproduction occur, but there is usually no definite succession of the two modes marking that alternation of sexual generation (gametophyte) and asexual generation (sporophyte) which characterizes the higher groups. The group has until recent years been regarded as comprising three classes distinguished by well-marked physiological features—the Algae (including the Seaweeds) which contain chlorophyll, the Fungi which have no chlorophyll and therefore lead a saprophytic or parasitic mode of life, and the Lichens which are composite organisms consisting of an alga and a fungus living together in a mutual parasitism (symbiosis); Bacteria were regarded as a section of Fungi. Such a system of classification, although convenient, is not the most natural one, and a sketch of the system which better expresses the relationships between the various subdivisions is given here. It has however been deemed advisable to retain the older groups for purpose of treatment in this work, and articles will be found under the headings Algae, Fungi, Bacteria, and Lichens. The study of phylogeny has suggested fourteen classes arranged in the following sequence: (1) Bacteria; (2) Cyanophyceae (Blue-green algae); (3) Flagellatae; (4) Myxomycetes (Slime-fungi); (5) Peridineae; (6) Conjugatae; (7) Diatomaceae (Diatoms); (8) Heteroconteae; (9) Chlorophyceae (Green Algae); (10) Characeae (Stoneworts); (11) Rhodophyceae (Red Algae); (12) Eumycetes (Fungi); (13) Phycomycetes (Algal fungi); (14) Phaeophyceae (Brown Algae). Bacteria (see Bacteriology) and Cyanophyceae (see Algae), which are often grouped together as Schizophyta, are from points of view of both structure and reproduction extremely simple organisms, and stand apart from the remaining groups, which are presumed to have originated directly or indirectly from the Flagellatae, a group of unicellular aquatic organisms combining animal and plant characteristics which may be regarded as the starting-point of unicellular Thallophytes on the one hand and of the Protozoa on the other. Thus simple forms included in the Heteroconteae, Chlorophyceae and Phaeophyceae show an obvious connexion with the Flagellatae; the Peridineae may be regarded as a further developed branch; the Conjugatae and Diatomaceae cannot be directly connected; the origin of the Rhodophyceae is also obscure; while the Characeae are an advanced and isolated group (see Algae). The Mycetozoa (q.v.) or Myxomycetes are a saprophytic group without chlorophyll of simple structure and isolated position. The algal fungi, Phycomycetes, are obviously derived from the Green Algae, while the remaining Fungi, the Eumycetes, appear to have sprung from the same stock as the Rhodophyceae (see Fungi). Owing to the similarity of structure and mode of life it is convenient to treat the Lichens (q.v.) as a distinct class, while recognizing that the component fungus and alga are representatives of their own classes.

The Bryophyta and Pteridophyta have sprung from the higher Thallophyta, and together form the larger group Archegoniatae, so-called from the form of the organ (archegonium) in which the egg-cell is developed. The Archegoniatae are characterized by a well-marked alternation of gametophyte and sporophyte generations; the former bears the sexual organs which are of characteristic structure and known as antheridia (male) and archegonia (female) respectively; the fertilized egg-cell on germination gives rise to the spore-bearing generation, and the spores on germination give rise directly or indirectly to a second gametophyte.

The Mosses and Liverworts (see Bryophyta) include forms with a more or less leaf-like thallus, such as many of the liverworts, and forms in which the plant shows a differentiation into a stem bearing remarkably simple leaves, as in the true mosses. They have no true roots, and their structure is purely cellular or conducting bundles of a very simple structure are present. The independent plant which is generally attached to the soil by hair-like structures is the sexual generation, the sporophyte is a stalked or sessile capsule