Page:The American Cyclopædia (1879) Volume I.djvu/663

 ARACHNIDA ARAFAT 627 ally on the head; in the legs heing usually 8, although in some species 6, and in others 10 ; and in their respiratory apparatus consisting of radiated tracheas. Most arachnids are carniv- orous. Some parasitic species, such as the mi- nute parasite mites, are furnished with a sucker, in some respects constructed like that of the gadfly. In other species there is a pair of upper jaws and a pair of under jaws carrying jointed feelers, and between them a sort of tongue formed by a projection from the breast. At the back of the mouth there is a piece of horny texture, termed by Savigny, Latreille, and Audouin the pharynx, forming the en- trance into the gullet. The gullet, the stom- ach, and the intestines run in a direct line from the pharynx to the vent. In most arach- nida there is a complete circulatory system of arteries and receiving veins, returning blood. The respiratory organs have two peculiarities, on which Latreille established his two great divisions of arachnida, pulmonaria and trache- aria. The pulmonaria, which Straus-Durck- heim and Leon Dufour place in the first or chief division, comprises the numerous species of spiders and the scorpions. Their respiratory apparatus consists of small cavities formed by the union of triangular laminae of extreme thin- ness. The division furnished with air pipes (trachearia) similar to those of insects, com- prises the harvest or shepherd spiders, mites, and other genera. " The presence of tracheae, or air pipes," says Latreille, "excludes all com- plete circulation; that is, the distribution of blood to different parts, and its return from the respiratory organs to the heart." The eyes of the arachnida are all simple. In most species of spiders they are 8 in number, but in some they are 6 and in others only 2. Nothing is known of the organs of hearing in arachnida, although it has been well ascertained that these animals do hear. Male spiders are always much smaller than the females. The palpi or feelers of the male are furnished with organs of various forms, usually bulging at the tip ; the feelers of the female gradually taper to a point. The eggs of spiders, not having a hard shell, are soft and compressible. Before being laid, they lie in the egg bag, squeezed together and flattened, within the spider's body, but assume the globular form after being laid. The female spider, in preparing a nest for her eggs, uses her own body as a bird uses its body to give form and proper size to its nest. The eggs are excluded from a cavity just behind the breast. The hatching of the eggs of one species (the epeira diadema) has been traced with care, and the successive evolution of the embryo depicted with skill, by Moritz Herold of Marburg. Latreille arranges the arachnida into two great orders, pulmonaria and tra- chearia. He subdivides the first order, A. pul- monaria, into two families, under the names of araneidce &nd.pedipalpi. The araneidm include our common spiders, having palpi simple, pedi- form ; mandibles armed with a movable and perforated claw, emitting a poisonous liquid; abdomen inarticulate, terminating by spinner- ets. The pedipalpi, including the scorpions and their allies, have the abdomen articulate, without spinnerets; palpi produced, cheliform (chela, claw), or shaped like pincers; mandi- bles with a movable digit. The second order, trachearia, includes various forms of shepherd spiders and sea spiders, mites, and ticks ; true mites, garden mites, spider mites, wood mites ; true ticks, -plant ticks, water ticks, harvest ticks ; false scorpions, book scorpions; shepherd spiders, sea spiders, and parasitic sea spiders. ARID, a town of Hungary, capital of the county of the same name, on the right bank of the Maros, 19 m. N. of Temesvar ; pop. in 1869, 32,725. It is the seat of a Greek bishop, and contains a gymnasium and Wallachian college. Considerable trade is carried on with Germany and the Black sea, chiefly in tobacco and cattle. Its annual fair is second only in importance to those of Pesth and Debreczin. In the 17th century the city was captured and destroyed by the Turks. It is skirted on two sides by the Maros, and defended by a fortress, which, held by the Austrians, capitulated only after a long siege to the Hungarian army in the revo- lutionary war of 1849. Three months later (Oct. 6), Arad witnessed the execution by the Austrian authorities of 13 Hungarian generals and colonels, who had surrendered with Gorgey at Vilagos (Aug. 13), or, following his exam- ple, a few days later. On the opposite bank, and connected by a bridge, is New Arad (Hun. Uj Arad), in the county of Ternes ; pop. 4,960. ARADUS (now Ruad), a rocky islet, about mile in circumference, lying 2 m. off the Syrian coast, in lat. 35 N., 35 m. N. of Tripoli. It was early occupied as a stronghold by the Phoenicians, known to the Hebrews as Arvad, a city second only to Tyre and Sidon, and held supremacy over a considerable tract on the ad- jacent mainland, where Antaradus was found- ed. The city shared in the general fortunes of Phoenicia, and about A. D. 638 was destroyed by Moawiyah, the lieutenant of the caliph Omar, and never rebuilt. Aradus is the only island on the Syrian coast mentioned by the historians of the crusades. It is now occu- pied by about 3,000 people, mainly fishermen. Remains of the old Phoenician walls are still to be seen. ARAFAT, or Orphat (Arabic, gratitude), a gra- nitic hill in Arabia, near Mecca, a pilgrimage to which is enjoined upon all who visit that city. It rises about 200 feet above the plain. The pilgrimage occupies three days from Mecca. On the second day the ceremony of the sermon on the mount is observed. The cadi of Mecca usually preaches the sermon, riding first upon a camel up the entire length of the stone steps which ascend the mountain to the summit. Hearing this sermon is the great point of the pilgrimage, and confers the title of hadji (pilgrim). There is a tradition among the Mohammedans that on this moun-