DICOTYLEDONS, in botany, the larger of the two great classes of angiosperms, embracing most of the common flower-bearing plants. The name expresses the most universal character of the class, the importance of which was first noticed by John Ray, namely, the presence of a pair of seed-leaves or cotyledons, in the plantlet or embryo contained in the seed. The embryo is generally surrounded by a larger or smaller amount of foodstuff (endosperm) which serves to nourish it in its development to form a seedling when the seed germinates; frequently, however, as in pea or bean and their allies, the whole of the nourishment for future use is stored up in the cotyledons themselves, which then become thick and fleshy. In germination of the seed the root of the embryo (radicle) grows out to get a holdfast for the plant; this is generally followed by the growth of the short stem immediately above the root, the so-called “hypocotyl,” which carries up the cotyledons above the ground, where they spread to the light and become the first green leaves of the plant. Protected between the cotyledons and terminating the axis of the plant is the first stem-bud (the plumule of the embryo), by the further growth and development of which the aerial portion of the plant, consisting of stem, leaves and branches, is formed, while the development of the radicle forms the root-system. The size and manner of growth of the adult plant show a great variety, from the small herb lasting for one season only, to the forest tree living for centuries. The arrangement of the conducting tissue in the stem is characteristic; a transverse section of the very young stem shows a number of distinct conducting strands—vascular bundles—arranged in a ring round the pith; these soon become united to form a closed ring of bast and wood, separated by a layer of formative tissue (cambium). In perennials the stem shows a regular increase in thickness each year by the addition of a new ring of wood outside the old one—for details of structure see Plants: Anatomy. A similar growth occurs in the root. This increase in the diameter of stem and root is correlated with the increase in leaf-area each season, due to the continued production of new leaf-bearing branches. A characteristic of the class is afforded by the complicated network formed by the leaf-veins,—well seen in a skeleton leaf, from which the soft parts have been removed by maceration. The parts of the flower are most frequently arranged in fives, or multiples of fives; for instance, a common arrangement is as follows,—five sepals, succeeded by five petals, ten stamens in two sets of five, and five or fewer carpels; an arrangement in fours is less frequent, while the arrangement in threes, so common in monocotyledons, is rare in dicotyledons. In some orders the parts are numerous, chiefly in the case of the stamens and the carpels, as in the buttercup and other members of the order Ranunculaceae. There is a very wide range in the general structure and arrangement of the parts of the flower, associated with the means for ensuring the transference of pollen; in the simplest cases the flower consists only of a few stamens or carpels, with no enveloping sepals or petals, as in the willow, while in the more elaborate type each series is represented, the whole forming a complicated structure closely correlated with the size, form and habits of the pollinating agent (see Flower). The characters of the fruit and seed and the means for ensuring the dispersal of the seeds are also very varied (see Fruit).
DICTATOR (from the Lat. dictare, frequentative of dicere, to speak). In modern usage this term is loosely used for a personal ruler enjoying extraordinary and extra-constitutional power. The etymological sense of one who “dictates”—i.e. one whose word (dictum) is law (from which that of one who “dictates,” i.e. speaks for some writer to record, is to be distinguished)—has been assisted by the historical use of the term, in ancient times, for an extraordinary magistrate in the Roman commonwealth. It is unknown precisely how the Roman word came into use, though an explanation of the earlier official title, magister populi, throws some light on the subject. That designation may mean “head of the (infantry) host” as opposed to his subordinate, the magister equitum, who was “head of the cavalry.” If this explanation be accepted, emphasis was thus laid in early times on the military aspect of the dictatorship, and in fact the office seems to have been instituted for the purpose of meeting a military crisis such as might have proved too serious for the annual consuls with their divided command. Later constitutional theory held that the repression of civil discord was also one of the motives for the institution of a dictatorship. Such is the view expressed by Cicero in the De legibus (iii. 3, 9) and by the emperor Claudius in his extant Oratio (i. 28). This function of the office, although it may not have been contemplated at first, is attested by the internal history of Rome. In the crisis of the agitation that gathered round the Licinian laws (367 B.C.) a dictator was appointed, and in 314 B.C. we have the notice of a dictator created for purposes of criminal jurisdiction (quaestionibus exercendis). The dictator appointed to meet the dangers of war, sedition or crime was technically described as “the administrative dictator” (rei gerundae causa). Minor, or merely formal, needs of the state might lead to the creation of other types of this office. Thus we find dictators destined to hold the elections, to make out the list of the senate, to celebrate games, to establish festivals, and to drive the nail into the temple of Jupiter—an act of natural magic which was believed to avert pestilence. These dictators appointed for minor purposes were expected to retire from office as soon as their function was completed. The “administrative dictator” held office for at least six months.
The powers of a dictator were a temporary revival of those of the kings; but there were some limitations to his authority. He was never concerned with civil jurisdiction, and was dependent on the senate for supplies of money. His military authority was confined to Italy; and his power of life and death over the citizens was at an early period limited by law. It was probably the lex Valeria of 300 B.C. that made him subject to the right of criminal appeal (provocatio) within the limits of the city. But during his tenure of power all the magistrates of the people were regarded as his subordinates; and it was even held that the right of assistance (auxilium), furnished by the tribunes of the plebs to members of the citizen body, should not be effectively exercised when the state was under this type of martial law. The dictator was nominated by one of the consuls. But here as elsewhere the senate asserted its authority over the magistrates, and the view was finally held that the senate should not only suggest the need of nomination but also the name of the nominee. After the nomination, the imperium of the dictator was confirmed by a lex curiata (see Comitia). To emphasize the superiority of this imperium over that of the consuls, the dictator might be preceded by twenty-four lictors, not by the usual twelve; and, at least in the earlier period of the office, these lictors bore the axes, the symbols of life and death, within the city walls.
Tradition represents the dictatorship as having a life of three centuries in the history of the Roman state. The first dictator is said to have been created in 501 B.C.; the last of the “administrative” dictators belongs to the year 216 B.C. It was an office that was incompatible both with the growing spirit of constitutionalism and with the greater security of the city; and the epoch of the Second Punic War was marked by experiments with the office, such as the election of Q. Fabius Maximus by the people, and the co-dictatorship of M. Minucius with Fabius, which heralded its disuse (see Punic Wars). The emergency office of the early and middle Republic has few points of contact, except those of the extraordinary position and almost unfettered authority of its holder, with the dictatorship as revised by Sulla and by Caesar. Sulla’s dictatorship was the form taken by a provisional government. He was created “for the establishment of the Republic.” It is less certain whether the dictatorships held by Caesar were of a consciously provisional character. Since the office represented the only supreme Imperium in Rome, it was the natural resort of the founder of a monarchy (see Sulla and Caesar). Ostensibly to prevent its further use for such a purpose, M. Antonius in 44 B.C. carried a law abolishing the dictatorship as a part of the constitution.
Bibliography.—Mommsen, Römisches Staatsrecht, ii. 141 foll. (3rd ed., Leipzig, 1887); Herzog, Geschichte und System der römischen Staatsverfassung, i. 718 foll. (Leipzig, 1884); Pauly-Wissowa, Realencyclopädie, v. 370 foll. (new edition, Stuttgart. 1893, &c.);
