were the chief people near the Greek and Roman colonies in | people, viz. their sedentary rather than nomad occupations, Syria and Mesopotamia. Classical writers use the term both their fondness for village life, for dancing, music and society, in its local and general sense. The Arabs to-day occupy, besides their cultivation of the soil, having more in common with African Arabia, a part of Mesopotamia, the western shores of the Red life than with that of the western Asiatic continent. (9) The Sea, the eastern coast of the Persian Gulf and the north of extreme facility of marriage which exists in all classes of the Africa. The finest type of the race is found in south Arabia southern Arabs with the African races, the fecundity of such among the Ariba Arabs, among the mountaineers of Hadramut unions and the slightness or even total absence of any caste and Yemen and among the Bedouin tribes roaming over the feeling between the dusky "pure" Arab and the still darker interior of central and northern Arabia. The Arabs of the African, pointing to a community of origin. And further argucoasts and those of Mesopotamia are hybrids, showing Turkish, ments were found in the characteristics of the Bedouins, their Negroid and Hamitic crossings. The people of Syria and pastoral and nomad tendencies; the peculiarities of their idiom Palestine are hybrids of Arab, Phoenician and Jewish descent. allied to the Hebrew; their strong clan feeling, their conThe theory that early Arab settlements were made on the east tinued resistance to anything like regal power or centralized coast of Africa as far as Sofala south of the Zambezi, is without organization. foundation; the earliest Arab settlement on the east coast of Africa that can be proved is Magadoxo (Mukdishu) in the 10th century, and the ruined cities of Mashonaland, once supposed to be the remains of Arab settlements, are now known to be of medieval African origin. On the East African coast-lands Arab influence is still considerable. Traces of the Arab type are met with in Asia Minor, the Caucasus, western Persia and India, while the influence of the Arab language and civilization is found in Europe (Malta and Spain), China and Central Asia. The Arabs are at once the most ancient as they in many ways are the purest surviving type of the true Semite. Certainly the inhabitants of Yemen are not, and in historic Ethnology. times never were, pure Semites. Somali and other elements, generally described under the collective racial name of Hamitic, are clearly traceable; but the inland Arabs still present the nearest approach to the primitive Semitic type. The origin of the Arab race can only be a matter of conjecture. From the remotest historic times it has been divided into two branches, which from their geographical position it is simplest to call the North Arabians and the South Arabians. Arabic and Jewish tradition trace the descent of the latter from Joktan (Arabic Kahtan) son of Heber, of the former from Ishmael. The South Arabians-the older branch-were settled in the south-western part of the peninsula centuries before the uprise of the Ishmaelites. These latter include not only Ishmael's direct descendants through the twelve princes (Gen. xxv. 16), but the Edomites, Moabites, Ammonites, Midianites and other tribes. This ancient and undoubted division of the Arab race -roughly represented to-day by the universally adopted classification into Arabs proper and Bedouin Arabs (see BEDOUINS)—has caused much dispute among ethnologists. All authorities agree in declaring the race to be Semitic in the broadest ethnological signification of that term, but some thought they saw in this division of the race an indication of a dual origin. They asserted that the purer branch of the Arab family was represented by the sedentary Arabs who were of Hamitic (Biblical Cushite), i.e. African ancestry, and that the nomad Arabs were Arabs only by adoption, and were nearer akin to the true Semite as sons of Ishmael. Many arguments were adduced in support of this theory. (1) The unquestioned division in remote historic times of the Arab race, and the immemorial hostility between the two branches. (2) The concurrence of pre-Islamitic literature and records in representing the first settlement of the "pure" Arab as made in the extreme south-western part of the peninsula, near Aden. (3) The use of Himyar, "dusky" or "red" (suggesting African affinities), as the name sometimes for the ruling class, sometimes for the entire people. (4) The African affinities of the Himyaritic language. (5) The resemblance of the grammar of the Arabic now spoken by the " pure" Arabs, where it differs from that of the North, to the Abyssinian grammar. (6) The marked resemblance of the pre-Islamitic institutions of Yemen and its allied provinces-its monarchies, courts, armies and serfs-to the historical Africo-Egyptian type and even to modern Abyssinia. (7) The physique of the " pure" Arab, the shape and size of the head, the slenderness of the lower limbs, all suggesting an African rather than an Asiatic origin. (8) The habits of the Such, briefly, were the more important arguments; but latterly ethnologists are inclined to agree that there is little really to be said for the African ancestry theory and that the Arab race had its beginning in the deserts of south Arabia, that in short the true Arabs are aborigines. Mahommedans call the centuries before the Prophet's birth waqt-el jahiliya, "the time of ignorance," but the fact is that the Arab world has in some respects never since reached so high a level as it had in those days which it suits Moslems to paint in dreary colours. Writing was a fine art and poetry flourished. Eloquence was an accomplishment all strove to acquire, and each year there were assemblies, lasting sometimes a month, which were devoted to contests of skill among the orators and poets, to listen to whose friendly rivalry tribesmen journeyed long distances. Last, that surest index of a people's civilization the treatment of women-contrasted very favourably with their position under the Koran. Women had rights and were respected. The veil and the harem system were unknown before Mahomet. According to Nöldeke the Nabataean inscriptions and coins show that women held a high social position in northern Arabia, owning large estates and trading independently. Polyandry and polygamy, it is true, were practised, but the right of divorce belonged to the woman as well as the man. Two kinds of marriage were celebrated. One was a purely personal contract, with no witnesses, the wife not leaving her home or passing under marital authority. The other was a formal marriage, the woman becoming subject to her husband by purchase or capture. Even captive women were not kept in slavery. Arabic wealth and culture had indeed thus early reached a stage which justified Professor Robertson Smith in writing, " In this period the name of Arab was associated to Western writers with ideas of effeminate indolence and peaceful opulence . . . the golden age of Yemen." But long before Mahomet's time this early Arab predominance was at an end, possibly due in great measure to the loss of the caravan trade through the increase of shipping. The abandonment of great cities and the ruin of many tribes contributed to the apparent nationalization of the Arab peoples. Though the traditional jealousy and hostility of the two branches, the Yemenites and Maadites or Ishmaelites, remained, the Arab world had attained by the levelling process of common misfortune the superficial unity it presents to-day. The nation thus formed, never a nation in the strict sense of the word, was distinctively and thoroughly Semitic in character and language, and has remained unchanged to the present day. The sporadic brilliancy of the ancient Arab kingdoms gave place to a social and political lethargy, the continuation of which for many centuries made the uprise of Saracenic empires seem a miracle to a world ignorant of the Arab past. The Arab race up to Mahomet's day had been in the main pagan. Monotheism, if it ever prevailed, early gave place to sun and star worship, or simple idolatry. Professor Robertson Smith suggests that totemism was the earliest form of Arabian idolatry, and that each tribe had its sacred animal. This he supports by the fact that some tribal names were derived from those of animals, and that animal-worship was not unknown in Arabia. What seems certain is that Arab religion was of a complex hybrid nature, not much to be wondered at when one remembers that Arabia was the asylum of many religious refugees, Zoroastrians, Jews, is a sacred duty everywhere in Arabia. Christians. In the later pre-Islamitic times spirits, or jinns, | years before, leads only too often to that blood-revenge which as they were called, of which each tribe or family had its own, were worshipped, and there was but a vague idea of a Supreme Being. Images of the jinns to the number of 360, one for each day of the lunar year, were collected in the temple at Mecca, the chief seat of their worship. That worship was of a sanguinary nature. Human sacrifice was fairly frequent. Under the guise of religion female infanticide was a common practice. At Mecca the great object of worship was a plain black stone, and to it pilgrimages were made from every part of Arabia. This stone was so sacred to the Arabs that even Mahomet dared not dispense with it, and it remains the central object of sanctity in the Ka'ba to-day. The temples of the Sabaeans and the Minaeans were built east of their cities, a fact suggesting sun-worship, yet this is not believed to have been the cult of the Minaeans. Common to both was the worship of Attar, the male Ashtoreth. There exist, however, marked tribal or almost semi-national diversities of character among the Arabs. Thus, the inhabitants of Hejaz are noted for courtesy and blamed for fickleness; those of Nejd are distinguished by their stern tenacity and dignity of deportment; the nations of Yemen are gentle and pliant, but revengeful; those of Hasa and Oman cheerful and fond of sport, though at the same time turbulent and unsteady. Anything approaching to a game is rare in Nejd, and in the Hejaz religion and the yearly occurrence of the pilgrim ceremonies almost exclude all public diversions; but in Yemen the well-known game of the "jerīd," or palm-stick, with dances and music is not rare. In Oman such amusements are still more frequent. Again in Yemen and Oman, coffee-houses, where people resort for conversation, and where public recitals, songs and other amusements are indulged in, stand open all day; while nothing With the appearance of Mahomet the Arabs took anew a place of the sort is tolerated in Nejd. So too the ceremonies of circumin the world's history. Physically the Arabs are one of the strongest and noblest races of the world. Baron de Larrey, surgeon-general to Physique. Napoleon on his expedition to Egypt and Syria, "" writes: Their physical structure is in all respects more perfect than that of Europeans; their organs of sense exquisitely acute, their size above the average of men in general, their figure robust and elegant, their colour brown; their intelligence proportionate to their physical perfection and without doubt superior, other things being equal, to that of other nations." The typical Arab face is of an oval form, leanfeatured; the eyes a brilliant black, deep-set under bushy eyebrows; nose aquiline, forehead straight but not high. In body the Arab is muscular and long-limbed, but lean. Deformed individuals or dwarfs are rare among Arabs; nor, except leprosy, which is common, does any disease seem to be hereditary among them. They often suffer from ophthalmia, though not in the virulent Egyptian form. They are scrupulously clean in their persons, and take special care of their teeth, which are generally white and even. Simple and abstemious in their habits, they often reach an extreme yet healthy old age; nor is it common among them for the faculties of the mind to give way sooner than those of the body. Character. cision or marriage are occasions of gaiety and pastime on the coast, but not in the central provinces. Manners and customs. An Arab town, or even village, except it be the merest hamlet, is invariably walled round; but seldom is a stronger material than dried earth used; the walls are occasionally flanked by towers of like construction. A dry ditch often surrounds the whole. The streets are irregular and seldom parallel. The Arab, indeed, lacks an eye for the straight. The Arab carpenter cannot form a right angle; an Arab servant cannot place a cloth square on a table. The Ka'ba at Mecca has none of its sides or angles equal. The houses are of one or two storeys, rarely of three, with flat mud roofs, little windows and no external ornament. If the town be large, the expansion of one or two streets becomes a marketplace, where are ranged a few shops of eatables, drugs, coffee, cottons or other goods. Many of these shops are kept by women. The chief mosque is always near the market-place; so is also the governor's residence, which, except in size and in being more or less fortified Arab fashion, does not differ from a private house. Drainage is unthought of; but the extreme dryness of the air obviates the inconvenience and disease that under other skies could not fail to ensue, and which in the damper climates of the coast make themselves seriously felt. But the streets are Thus, physically, they yield to few races, if any, of mankind; roughly swept every day, each householder taking care of the mentally, they surpass most, and are only kept back in the roadway that lies before his own door. Whitewash and colour march of progress by the remarkable defect of or- are occasionally used in Yemen, Hejaz and Oman; elsewhere a ganizing power and incapacity for combined action. light ochre tint, the colour of the sun-dried bricks, predominates, Lax and imperfect as are their forms of government, it is with and gives an Arab town the appearance at a distance of a impatience that even these are borne; of the four caliphs | large dust-heap in the centre of the bright green ring of gardens who alone reigned—if reign theirs could be called-in Arabia | and palm-groves. Baked bricks are unknown in Arabia, and proper, three died a violent death; and of the Wahhabi princes, the most genuine representatives in later times of pure Arab rule, almost all have met the same fate. The Arab face, which is not unkindly, but never smiling, expresses that dignity and gravity which are typical of the race. While the Arab is always polite, good-natured, manly and brave, he is also revengeful, cruel, untruthful and superstitious. Of the Arab nature Burckhardt (other authorities, e.g. Barth and Rohlfs, are far less complimentary) wrote: "The Arab displays his manly character when he defends his guest at the peril of his own life, and submits to the reverses of fortune, to disappointment and distress, with the most patient resignation. He is distinguished from a Turk by the virtues of pity and gratitude. The Turk is cruel, the Arab of a more kind temper; he pities and supports the wretched, and never forgets the generosity shown to him even by an enemy.' The Arab will lie and cheat and swear false oaths, but once his word is pledged he may be trusted to the last. There are some oaths such as Wallah (by Allah) which mean nothing, but such an oath as the threefold one with wa, bi and ta as particles of swearing the meanest thief will not break. In temper, or at least in the manifestation of it, the Arab is studiously calm; and he rarely so much as raises his voice in a dispute. But this outward tranquillity covers feelings alike keen and permanent; and the remembrance of a rash jest or injurious word, uttered stone buildings are rare, especially in Nejd. Palm branches and the like, woven in wattles, form the dwellings of the poorer classes in the southern districts. Many Arab towns possess watch-towers, like huge round factory chimneys in appearance, built of sun-dried bricks, and varying in height from 50 to 100 ft. or even more. Indeed, two of these constructions at the town of Birkat-el-Mauj, in Oman, are said to be each of 170 ft. in height, and that of Nezwah, in the same province, is reckoned at 140; but these are of stone. The principal feature in the interior of an Arab house is the "kahwah " or coffee-room. It is a large apartment spread with mats, and sometimes furnished with carpets and a few cushions. At one end is a small furnace or fireplace for preparing coffee. In this room the men congregate; here guests are received, and even lodged; women rarely enter it, except at times when strangers are unlikely to be present. Some of these apartments are very spacious and supported by pillars; one wall is usually built transversely to the compass direction of the Ka'ba; it serves to facilitate the performance of prayer by those who may happen to be in the kahwah at the appointed times. The other rooms are ordinarily small. The Arabs are proverbially hospitable. A stranger's arrival is often the occasion of an amicable dispute among the wealthier inhabitants as to who shall have the privilege of receiving him. Arab cookery is of the simplest. Roughly-ground wheat cooked with butter; bread in thin cakes, prepared on a heated iron plate or against the walls of an open oven; a few vegetables, generally of the leguminous kinds; boiled mutton or camel's flesh, among the wealthy; dates and fruits-this is the menu of an ordinary meal. Rice is eaten by the rich and fish is common on the coasts. Tea, introduced only a few decades back, is now largely drunk. A food of which the Arabs are fond is locusts boiled in salt and water and then dried in the sun. They taste like stale shrimps, but there is a great sale for them. Spices are freely employed; butter much too largely for a European taste. After eating, the hands are always washed, soap or the ashes of an alkaline plant being used. A covered censer with burning incense is then passed round, and each guest perfumes his hands, face, and sometimes his clothes; this censer serves also on first receptions and whenever special honour is intended. In Yemen and Oman scented water often does duty for it. Coffee, without milk or sugar, but flavoured with an aromatic seed brought from India, is served to all. This, too, is done on the occasion of a first welcome, when the cups often make two or three successive rounds; but, in fact, coffee is made and drunk at any time, as frequently as the desire for it may suggest itself; and each time fresh grains are sifted, roasted, pounded and boiled-a very laborious process, and one that requires in the better sort of establishments a special servant or slave for the work. Arabs generally make but one solid meal a day-that of supper, soon after sunset. Even then they do not eat much, gluttony being rare among them, and even daintiness esteemed disgraceful. Wine, like other fermented drinks, is prohibited by the Koran, and is, in fact, very rarely taken, though the inhabitants of the mountains of Oman are said to indulge in it. On the coast spirits of the worst quality are sometimes procured; opium and hashish are sparingly indulged in. On the other hand, wherever Wahhābiism has left freedom of action, tobaccosmoking prevails; short pipes of clay, long pipes with large open bowls, or most frequently the water-pipe or "narghileh," being used. The tobacco smoked is generally strong and is either brought from the neighbourhood of Bagdad or grown in the country itself. The strongest quality is that of Oman; the leaf is broad and coarse, and retains its green colour even when dried; a few whiffs have been known to produce absolute stupor. The aversion of the Wahhabis to tobacco is well known; they entitle it "mukhzi " or "the shameful," and its use is punished with blows, as the public use of wine would be elsewhere. Dress. In dress much variety prevails. The loose cotton drawers girded at the waist, which in hot climates do duty for trousers, are not often worn, even by the upper classes, in Nejd or Yemama, where a kind of silk dressing-gown is thrown over the long shirt; frequently, too, a brown or black cloak distinguishes the wealthier citizen; his head-dress is a handkerchief fastened round the head by a band. But in Hejaz, Yemen and Oman, turbans are by no means uncommon; the ordinary colour is white; they are worn over one or more skullcaps. Trousers also form part of the dress in the two former of these districts; and a voluminous sash, in which a dagger or an inkstand is stuck, is wrapped round the waist. The poorer folk, however, and the villagers often content themselves with a broad piece of cloth round the loins, and another across the shoulders. In Oman trousers are rare, but over the shirt a long gown, of peculiar and somewhat close-fitting cut, dyed yellow, is often worn. The women in these provinces commonly put on loose drawers and some add veils to their head-dresses; they are over-fond of ornaments (gold and silver); their hair is generally arranged in a long plait hanging down behind. All men allow their beards and moustaches full growth, though this is usually scanty. Most Arabs shave their heads, and indeed all, strictly speaking, ought by Mahommedan custom to do so. An Arab seldom or never dyes his hair. Sandals are worn more often than shoes; none but the very poorest go barefoot. Slavery is still, as of old times, a recognized institution through out Arabia; and an illicit traffic in blacks is carried on along the coasts of the Persian Gulf and the Red Sea. The Slavery. slaves themselves were obtained chiefly from the east African coast districts down as far as Zanzibar, but this source of supply was practically closed by the end of the 19th century. Slaves are usually employed in Arabia as herdsmen or as domestic servants, rarely in agricultural work; they also form a considerable portion of the bodyguards with which Eastern greatness loves to surround itself. Like their countrymen elsewhere, they readily embrace the religion of their masters and become zealous Mahommedans. Arab custom enfranchises a slave who has accepted Islam at the end of seven years of bondage, and when that period has arrived, the master, instead of exacting from his slave the price of freedom, generally, on giving him his liberty, adds the requisite means for supporting himself and a family in comfort. Further, on every important occasion, such as a birth, circumcision, a marriage or a death, one or more of the household slaves are sure of acquiring their freedom. Hence Arabia has a considerable free black population; and these again, by inter-marriage with the whites around, have filled the land with a mulatto breed of every shade, till, in the eastern and southern provinces especially, a white skin is almost an exception. In Arabia no prejudice exists against negro alliances; no social or political line separates the African from the Arab. A negro may become a sheik, a kadi, an amir, or whatever his industry and his talents may render him capable of being. This is particularly so in Nejd, Yemen and Hadramut; in the Hejaz and the north a faint line of demarcation may be observed between the races. The Arabs are good soldiers but poor generals. Personal courage, wonderful endurance of privation, fixity of purpose, and a contempt of death are qualities common to almost every race, tribe and clan that compose the Arab nation. In skirmishing and harassing they have few equals, while at close quarters they have often shown themselves capable of maintaining, armed with swords and spears alone, a desperate struggle against guns and bayonets, neither giving nor receiving quarter. Nor are they wholly ignorant of tactics, their armies, when engaged in regular war, being divided into centre and wings, with skirmishers in front and a reserve behind, often screened at the outset of the engagement by the camels of the expedition. These animals, kneeling and ranged in long parallel rows, form a sort of entrenchment, from behind which the soldiers of the main body fire their matchlocks, while the front divisions, opening out, act on either flank of the enemy. This arrangement of troops may be traced in Arab records as far back as the 5th century, and was often exemplified during the Wahhābi wars. Military qualities. Arab women are scarcely less distinguished for their bravery than the men. Records of armed heroines occur frequently in the chronicles or myths of the pre-Islamitic time; and in authentic history the Battle of the Camel, 656 A.D., where Ayesha, the wife of Mahomet, headed the charge, is only the first of a number of instances in which Arab amazons have taken, sword in hand, no inconsiderable share in the wars and victories of Islam. Even now it is the custom for an Arab force to be always accompanied by some courageous maiden, who, mounted on a blackened camel, leads the onslaught, singing verses of encouragement for her own, of insult for the opposing tribe. Round her litter the fiercest of the battle rages, and her capture or death is the signal of utter rout; it is hers also to head the triumph after the victory of her clan. There is little education, in the European sense of the word, in Arabia. Among the Bedouins there are no schools, and few, even of the most elementary character, in the towns Education. or villages. Where they exist, little beyond the mechanical reading of the Koran, and the equally mechanical learning of it by rote, is taught. On the other hand, Arab malechildren, brought up from early years among the grown-up men of the house or tent, learn more from their own parents and at home than is common in other countries; reading and writing are in most instances thus acquired, or rather transmitted; besides such general principles of grammar and eloquence, often of poetry and history, as the elders themselves may be able to impart. To this family schooling too are due the good manners, politeness, and self-restraint that early distinguish Arab children. In the very few instances where a public school of a higher class exists, writing, grammar and rhetoric sum up its teachings. Law and theology, in the narrow sense that both these words have in the Islamitic system, are explained in afternoon lectures given in most mosques; and some verses of the Koran, with one of the accepted commentaries, that of Baidawi for example, form the basis of the instruction. Great attention is paid to accuracy of grammar and purity of diction throughout Arabia; yet something of a dialectic difference may be observed in the various districts. The purest Arabic, that which is as nearly as possible identical in the choice of words and in its inflections with the language of the Koran, is spoken in Nejd, and the best again of that in the province of Suder. Next in purity comes the Arabic of Shammar. Throughout the Hejaz in general, the language, though extremely elegant, is not equally correct; in el-Hasa, Bahrein and Oman it is decidedly influenced by the foreign element called Nabataean. In Yemen, as in other southern districts of the peninsula, Arabic merges insensibly into the Himyaritic or African dialect of Hadramut and Mahra. (See SEMITIC LANGUAGES.) BIBLIOGRAPHY.-Lieutenant Wellsted, Travels in Arabia (Lond., 1838); "Narrative of a Journey to the Ruins of Nakeb el Hajar (Jour. R. Geog. Soc. vii. 20); Carsten Niebuhr, Travels through Arabia (transl. into English by Robert Heron, 2 vols., Edin., 1792); John Lewis Burckhardt, Travels in Arabia (2 vols., Lond., 1829); Notes on the Bedouins and Wahabis, (2 vols., Lond., 1830; in German, Weimar, 1831); C. J. Cruttenden, Journal of an Excursion to Sana'a, the Capital of Yemen (Bombay, 1838); A. Sprenger, Die alte Geographie Arabiens als Grundlage der Entwicklungsgeschichte des Semitismus (Berne, 1875); Sir Richard F. Burton, Personal Narrative of a Pilgrimage to El Medinah and Meccah (Lond., 1855); W. Robertson Smith, Kinship and Marriage in Early Arabia (Cambridge); E. Reclus, Les Arabes (Brussels, 1898); Lady Anne Blunt, A Pilgrimage to Nejd (2 vols., Lond., 1881); C. M. Doughty, Arabia Deserta (2 vols., 1888); Rev. S. M. Zwemer, Arabia: the Cradle of Islam (1900); Albrecht Zehme, Arabien und die Araber, seit hundert Jahren (1875). ARACAJÚ, a city and seaport of Brazil, capital of the state of Sergipe, 170 m. N.N.E. of Bahia, on the river Cotinguiba, or Cotindiba, 6 m. from the coast. The municipality, of which it forms a part, had a population in 1890 of 16,336, about twothirds of whom lived in the city itself. Aracajú is a badly built town on the right bank of the river at the base of a ridge of low sand-hills and has the usual features of an unprogressive provincial capital. Good limestone is quarried in its vicinity, and the country tributary to this port produces large quantities of sugar. Cotton is also grown, and the back country sends down hides and skins for shipment. The anchorage is good, but a dangerous bar at the mouth of the river prevents the entrance of vessels drawing more than 12 ft. The port is visited, therefore, only by the smaller steamers of the coastwise lines. The river is navigable as far as the town of Maroim, about 10 m. beyond Aracajú. The city was founded in 1855. ARACATY, or ARACATÍ, a city and port of Brazil, in the state of Ceará, 75 m. 3.E. of Fortaleza, on the river Jaguaribe, 8 m. from the sea. Pop. of the municipality (1890) 20,182, of whom about 12,000 belonged to the city. A dangerous bar at the mouth of the river permits the entrance only of the smaller coasting steamers, but the port is an important commercial centre, and exports considerable quantities of cotton, hides, maniçoba, rubber, fruit, and palm wax. it to pieces. Arachne hanged herself in despair; but the goddess out of pity loosened the rope, which became a cobweb, while Arachne herself was changed into a spider (Ovid, Metam. vi. 5-145). The story probably indicates the superiority of Asia over Greece in the textile arts. ARACHNIDA, the zoological name given in 1815 by Lamarck (Gr. àpáxvn, a spider) to a class which he instituted for the reception of the spiders, scorpions and mites, previously classified by Linnaeus in the order Aptera of his great group Insecta. Lamarck at the same time founded the class Crustacea for the lobsters, crabs and water-fleas, also until then included in the order Aptera of Linnaeus. Lamarck included the Thysanura and the Myriapoda in his class Arachnida. The Insecta of Linnaeus was a group exactly equivalent to the Arthropoda founded a hundred years later by Siebold and Stannius. It was thus reduced by Lamarck in area, and made to comprise only the six-legged, wing-bearing "Insecta." For these Lamarck proposed the name Hexapoda; but that name has been little used, and they have retained to this day the title of the much larger Linnaean group, viz. Insecta. The position of the Arachnida in the great sub-phylum Arthropoda, according to recent anatomical and embryological researches, is explained in the article ARTHROPODA. The Arachnida form a distinct class or line of descent in the grade Euarthropoda, diverging (perhaps in common at the start with the Crustacea) from primitive Euarthropods, which gave rise also to the separate lines of descent known as the classes Diplopoda, Crustacea, Chilopoda and Hexapoda. ARACHNE, in Greek mythology, the daughter of Idmon of Colophon in Lydia, a dyer in purple. She had acquired such skill in the art of weaving that she ventured to challenge Athena. While the goddess took as subjects her quarrel with Poseidon as to the naming and possession of Attica, and the warning examples of those who ventured to pit themselves against the immortals, Arachne depicted the metamorphoses of the gods and their amorous adventures. Her work was so perfect that Athena, enraged at being unable to find any blemish in it, tore (From Lankester, Q. J. Mic. Sci., N.S. vol. xxiv., 1884.) Limulus an Arachnid.-Modern views as to the classification and affinities of the Arachnida have been determined by the demonstration that Limulus and the extinct Eurypterines (Pterygotus, &c.) are Arachnida; that is to say, are identical in the structure and relation of so many important parts with Scorpio, whilst differing in those respects from other Arthropoda, that it is impossible to suppose that the identity is due to homoplasy or convergence, and the conclusion must be accepted that the resemblances arise from close genetic relationship. The view that Limulus, the king-crab, is an Arachnid was maintained as long ago as 1829 by Strauss-Dürckheim (1), on the ground of its possession of an internal cartilaginous sternum-also possessed by the Arachnida (see figs. 1, 2, 3, 4, 5 and 6)—and of the similarity of the disposition of the six leg-like appendages around the mouth in the two cases (see figs. 45 and 63). The evidence of the exact equivalence of the segmentation and appendages of Limulus and Scorpio, and of a number of remarkable points of agreement in structure, was furnished by Ray Lankester in an article published in 1881 ("Limulus an Arachnid," Quart. Journ. Micr. Sci. vol. xxi. N.S.), and in a series of subsequent memoirs, in which the structure of the entosternum, of the coxal glands, of the eyes, of the veno-pericardiac muscles, of the The various comparisons previously made between the structure of Limulus and the Eurypterines on the one hand, and that of a typical Arachnid, such as Scorpio, on the other, had been vitiated by erroneous notions as to the origin of the nerves supplying the anterior appendages of Limulus (which were finally removed by Alphonse Milne-Edwards in his beautiful memoir (6) on the structure of that animal), and secondly by the erroneous identification of the double sternal plates of Limulus, called "chilaria," by Owen, with a pair of appendages (7). Once the identity of the chilaria with the pentagonal sternal plate of the scorpion is recognized CO-an identification first insisted on by Lankester-the whole series of segments and appendages in the two animals, Limulus and Scorpio, are seen to correspond most closely, segment for segment, with one another (see figs. 7 and 8). The structure of the prosomatic appendages or legs is also seen to present many significant points of agreement (see figures), but a curious discrepancy existed in the six-jointed structure of the limb in Limulus, which differed from the seven-jointed limb of Scorpio by the defect of one joint. R. I. Pocock of the British Museum has observed that in Limulus a marking exists on the fourth joint, which apparently indicates a previous -montiert od AC my masboM pf, Posterior flap or diaphragm of New port. m2 and m2, Perforations of the diaphragm for the passage of muscles. DR, The paired dorsal ridges. GC, Gastric canal or foramen. AC, Arterial canal or foramen. (After Lankester, loc. cit.) | or division of this segment into two, and thus establishes the agreement of Limulus and Scorpio in this small feature of the number of segments in the legs (see fig. 11). full description of the limbs and segments of Limulus and Scorpio. It is not desirable to occupy the limited space of this article by a The reader is referred to the complete series of figures here given, with their explanatory legends (figs. 12, 13, 14, 15). Certain matters, however, require comment and explanation to render the comparison intelligible. The tergites, or chitinized dorsal halves of the body rings, are fused to form a prosomatic carapace," carapace of the prosoma, in both Limulus and Scorpio (see figs, 7 and 8). This region corresponds in both cases to six somites, as indicated by the presence of six pairs of limbs. On the surface of the carapace there are in both animals a pair of central eyes with simple lens pf.... and a pair of lateral eyetracts, which in Limulus consist of closely-aggregated simple eyes, forming a compound eye, whilst in Scorpio they present several separate small eyes. The central and the lateral eyes entosternum as that drawn in fig. 3. microscopic structure of the FIG. 4.-Ventral surface of the same has been shown by Lankester Letters as in fig. 3 with the addition and A. G. Bourne (5) to of NC, neural canal or foramen. differ; but the lateral eyes of (After Lankester, loc. cit.) Scorpio were shown by them to be similar in structure to the lateral eyes of Limulus, and the central eyes of Scorpio to be identical in structure with the central eyes of Limulus (see below). (From Lankester, loc. cit.) Following the prosoma is a region consisting of six segments (figs. 14 and 15), each carrying a pair of plate-like appendages in both Limulus and Scorpio. tergites of this region and those of the This region is called the mesosoma. The following region, the metasoma, are fused to form a second or posterior carapace in Limulus, whilst remaining free in Scorpio. The first pair of foliaceous appendages in each animal is the genital operculum; beneath it are found the openings of the genital ducts. The second pair of mesosomatic appendages in Scorpio are known as the pectens." Each consists of an axis, bearing numerous blunt tooth-like pro- FIG. 5.-Entosternum of cesses arranged in a series. This is one of the mygalomorphous represented in Limulus by the first gill- spiders; ventral surface. bearing appendage. The leaves (some Ph.N., pharyngeal notch. 150 in number) of the gill-book (see The posterior median profigure) correspond to the tooth-like cess with its repetition of processes of the pectens of Scorpio. triangular segments closely The next four pairs of appendages (com- resembles the same process pleting the mesosomatic series of six) in Limulus. consist, in both Scorpio and Limulus, of a base carrying each 130 to 150 blood-holding, leaf-like plates, lying on one another like the leaves of a book. Their minute structure is closely similar in the two cases; the leaf-like plates receive blood from the great sternal sinus, and serve as respiratory organs. The difference between the gill-books of Limulus and the lung-books of latter are adapted to aerial respiraScorpio depends on the fact that the tion, while the former serve for aquatic respiration. The appendage carrying the gill-book stands out on the surface of the body in Limulus, besides the gill-book and its base; and has other portions developed it is fused with its fellow of the opposite side On the other hand, in Scorpio, the gill-book-bearing appendage has sunk below the surface, forming a recess or chamber for the itself, which communicates with the that drawn in fig. 5. Ph.N., exterior by an oval or circular pharyngeal notch. in-sinking has taken place, and that the lung-books or in-sunken "stigma (fig. 10, stg). That this (Atter Lankester, loc. cit.) gill-books of Scorpio really represent appendages (that is to say, limbs or parapodia) is proved by their developmental history (see |
