to the mode of life of the plant. For instance, some species of Philodendron have a growth like that of ivy, with feeding roots penetrating the soil and clasping roots which fix the plant to its support. In other species of the genus the seed germinates on a branch, and the seedling produces clasping roots, and roots which grow downwards hanging like stout cords, and ultimately reaching the ground. The leaves, which show great variety in size and form, are generally broad and net-veined, but in sweet-flag (Acorus Calamus) are long and narrow with parallel veins. In Arum the blade is simple, as also in the so-called arum-lily (Richardia), a South African species common in Britain as a greenhouse plant, and in Caladium, a tropical South American genus, and Alocasia (tropical Asia), species of which are favourite warm-greenhouse plants on account of their variegated leaves. In other genera the leaves are much divided and sometimes very large; those of Dracontium (tropical America) may be 15 ft. high, with a long stem-like stalk and a much-branched spreading blade. The East Indian genus Amorphophallus has a similar habit. A good series of tropical aroids is to be seen in the aroid house at Kew. The so-called water cabbage (Pistia Stratiotes) is a floating plant widely distributed in the tropics, and consisting of rosettes of broadish leaves several inches across and a tuft of roots hanging in the water.
| |
| Arum maculatum, Cuckoo-pint | |
| 1. Leaves and inflorescence. | succession (from below) female |
| 2. Underground root-stock. | flowers, male flowers, and sterile |
| 3. Lower part of spathe cut open. | flowers forming a ring of hairs |
| 4. Spike of fruits. Showing in | borne on the spadix. |
The small flowers are densely crowded on thick fleshy spikes, which are associated with, and often more or less enveloped by, a large leaf (bract), the so-called spathe, which, as in cuckoo-pint, where it is green in colour, Richardia, where it is white, creamy or yellow, Anthurium, where it is a brilliant scarlet, is often the most striking feature of the plant. The details of the structure of the flower show a wide variation; the flowers are often extremely simple, sometimes as in Arum, reduced to a single stamen or pistil. The fruit is a berry—the scarlet berries of the cuckoo-pint are familiar objects in the hedges in late summer. The plants generally contain an acrid poisonous juice. The underground stems (rhizomes or tubers) are rich in starch; from that of Arum maculatum Portland arrowroot was formerly extensively prepared by pounding with water and then straining; the starch was deposited from the strained liquid.
The order is represented in Britain by Arum maculatum, a low herbaceous plant common in woods and hedgerows in England, but probably not wild in Scotland. It grows from a whitish root-stock which sends up in the spring a few long-stalked, arrow-shaped leaves of a polished green, often marked with dark blotches. These are followed by the inflorescence, a fleshy spadix bearing in the lower part numerous closely crowded simple unisexual flowers and continued above into a purplish or yellowish appendage; the spadix is enveloped by a leafy spathe, constricted in the lower part to form a chamber, in which are the flowers. The mouth of this chamber is protected by a ring of hairs pointing downwards, which allow the entrance but prevent the escape of small flies; after fertilization of the pistils the hairs wither. The insects visit the plant in large numbers, attracted by the foetid smell, and act as carriers of the pollen from one spathe to another. As the fruit ripens the spathe withers, and the brilliant red berries are exposed.
The sweet-flag Acorus Calamus (q.v.), which occurs apparently wild in England in ditches, ponds, &c., is supposed to have been introduced.
AROLSEN, a town of Germany, capital of the principality of Waldeck, 25 m. N.W. of Cassel, with which it is connected by rail via Warburg. Pop. 3000. It lies in a pleasant undulating country at an elevation of 900 ft. above the sea. The Evangelical parish church contains some fine statues by Christian Rauch, and the palace (built 1710–1720), in addition to a valuable library of 30,000 vols., a collection of coins and pictures, among the latter several by Angelica Kauffmann. Arolsen is the birthplace of the sculptor C. Rauch and of the painters Wilhelm and Friedrich Kaulbach.
ARONA, a town of Piedmont, Italy, in the province of Novara, on the W. bank of Lake Maggiore, 3 m. from its S. extremity, 23 m. N. of Novara, and 42 m. N.W. of Milan by rail. Pop. (1901) 4700. It is a railway centre of some importance on the Simplon line, and is also the southern terminus of the steamers which ply on Lake Maggiore. The church of S. Maria contains a fine altar-piece by Gaudenzio Ferrari. On a hill to the north of the town stands a colossal bronze statue of S. Carlo Borromeo (born here in 1538), erected in 1697. The pedestal, of red granite, is 42 ft. high, and the statue 70 ft. high; the latter is hollow, and can be ascended from within.
ARPEGGIO (from Ital. arpeggiare, to play upon the harp), in music, the notes of a chord, played in rapid succession as on a harp, and not together.
ARPI (Gr. Ἀργόριππα), an ancient city of Apulia, 20 m. W. of the sea coast, and 5 m. N. of the modern Foggia. The legend attributes its foundation to Diomedes, and the figure of a horse, which appears on its coins, shows the importance of horse-breeding in early times in the district. Its territory extended to the sea, and Strabo says that from the extent of the city walls one could gather that it had once been one of the greatest cities of Italy. As a protection against the Samnites Arpi became an ally of Rome, and remained faithful until after the battle of Cannae, but Fabius captured it in 213 B.C., and it never recovered its former importance. It lay on a by-road from Luceria to Sipontum. No Roman inscriptions have, indeed, been found here, and remains of antiquity are scanty. Foggia is its medieval representative. (T. As.)
ARPINO (anc. Arpinum), a town of Campania, Italy, in the province of Caserta, 1475 ft. above sea-level; 12 m. by rail N.W. of Roccasecca, a station on the railway from Naples to Rome. Pop. (1901) 10,607. Arpino occupies the lower part of the site of the ancient Volscian town of Arpinum, which was finally taken from the Samnites by the Romans in 305 B.C. It became a civitas sine suffragio, but received full privileges (civitas cum suffragio) in 188 B.C. with Formiae and Fundi; it was governed as a praefectura until the Social War, and then became a municipium. The ancient polygonal walls, which are still finely preserved, are among the best in Italy. They are built of blocks of pudding-stone, originally well jointed, but now much weathered. They stand free in places to a height of 11 ft., and are about 7 ft. wide at the top. A single line of wall, with medieval round towers at intervals, runs on the north side from the present town to Civitavecchia (2055 ft.), on the site of the ancient citadel. Here is the Porta dell’ Arco, a gate of the old wall, with an aperture 15 ft. high, formed by the gradual inclination of the two sides towards one another. Below Arpino, in the valley of the Liris, between the two arms of its tributary the Fibrenus, and 34 m. north of Isola del Liri, lies the church of S. Domenico, which marks the site of the villa in which Cicero was born and frequently resided. Near it is an ancient bridge, of a road which crossed the Liris to Cereatae (modern Casamari). The painter Giuseppe Cesari (1560–1640), more often known as the Cavaliere d’ Arpino, was also born here.
See O. E. Schmidt, Arpinum, eine topographisch-historische Skizze (Meissen, 1900). (T. As.)
ARQUÀ PETRARCA, a village of Venetia, Italy, in the province of Padua, 3 m. to the S.W. of Battaglia. Pop. (1901) 1573. It is chiefly famous as the place where Petrarch lived his last few years and died in 1374. His house still exists, and his tomb, a sarcophagus supported by four short columns of red marble, stands in front of the church. Near Arquà, on the banks of the small Lago della Costa, is the site of a prehistoric lake village, excavations in which have produced interesting results.
See A. Moschetti and F. Cordenone in Bollettino del Museo Civico di Padova, iv. (1901), 102 seq.
ARQUEBUS (also called harquebus, hackbut, &c.), a firearm of the 16th century, the immediate predecessor of the musket. The word itself is certainly to be derived from the German Hakenbühse (mod. Hakenbüchse, cf. Eng. hackbut and hackbush), “hook gun.” The “hook” is often supposed to refer to the bent shape of the butt, which differentiated it from the straight-stocked hand gun, but it has also been suggested that the original arquebus had a metal hook near the muzzle, which was used to grip the wall (or other fixed object) so as to steady the aim and take up the force of recoil, that from this
