SEROUS MEMBRANES tunica vaginalis testis, and the synovial fluid; (2) the tears, and the fluids existing in the eyeball, the amniotic fluid, and transudations into the tissue of organs; (3) morbid or excessive transudations, such as dropsical fluids, the fluids occurring in hydatids, and in blebs and vesicles on the skin, and transudations from the blood in the intestinal capillaries, as in cases of intestinal catarrh, cholear, or dysentery. All these fluids bear a close resemblance to one another, both in their physical and chemical characters. In so far as relates to their physical characters they are usually clear and transparent, colourless or slightly yellow, of a slight saline, mawkish taste, and exhibiting an alkaline reaction with test-paper. They possess no special formal or histological elements, but on a microscopic examination blood-corpuscles, cells of various kinds, molecular granules, and epithelium may occasionally be observed in them. The ordinary chemical constituents of these fluids are water, fibrin (occasionally), albumen, the fats, animal soaps, cholesterin, extractive matters, urea (occasionally), the same inorganic salts which are found in the serum of the blood, and the same gases as occur in the blood. Serous Membranes. There are six of these membranes in the human body, two being median and single, while two are double and lateral. They are the pericardium and the peritoneum, with the two pleure and tunica vaginales testis. They are all closed sacs, with one exception; and each sac or continuous membrane consists of two portions-a parietal one, which lines the walls of the cavity, and a visceral or reflected one, which forms an almost complete coating or investment for the viscera contained in the cavity. The interior of the sac contains a small quantity of fluid, usually merely enough to moisten the contiguous surfaces and thereby enable them to glide easily upon each other. With regard to their structure, it is sufficient to state that they consist essentially of (1) endothelium; (2) basement membrane; (3) a stratum of areolar or cellular tissue, which constitutes the chief thickness of the membrane, and is the constituent on which its physical properties are mainly dependent. This layer is more liable to variation than the others, and one of the most common alterations is an augmentation of the yellow fibrous element, by which an increased elasticity is given to the membrane, which is thus better adapted for distention, and for a subsequent return to its original bulk. The situations in which this augmentation is found are, as Dr Brinton (Cyclopaedia of Anatomy and Physiology, vol. iv. p. 524) has pointed out, in exact conformity with this view: in the peritoneum, which lines the anterior abdominal wall and covers the bladder, it attains its maximum; in the detached folds of the mesentery, in the costal pleura, and in the suspensory ligament of the liver it is still very prominent; while on the posterior wall of the belly, and in serous membranes covering the heart, liver, &c. it is almost absent. For some of the principal serous membranes, see the articles PERICARDIUM, PERITONEUM, PLEURISY, and RESPIRATION (Vol. VIII. p. 660).—Synovial membranes (q.v.) present many points of similarity to serous membranes. Serpent, a bass musical wind-instrument entirely obsolete except in a few continental churches. It is said to have been invented by a French priest at Auxerre in 1590. It consists of a tapered tube 8 feet long, built of wood and covered with leather, and twisted about like a serpent, whence the name. It is sounded through a cupped mouthpiece like that of the bass Trombone (q.v.). It had originally six holes for three fingers of each hand, but in its later years had keys added. The Serpent. Serpentine, a mineral composed of silica and magnesia in almost equal proportions, with about 13-15 per cent. of water, and a little protoxide of iron. Serpentine in crystals, save occurs generally massive; never morphs; colour some shade of as pseudogreen, also red and brownish yellow; has a smooth but sometimes greasy feel; is soft enough to be scratched with calcite. Precious Serpentine, rich, dark-green colour, hard or Noble Serpentine, is of a enough to receive a good polish, translucent, and sometimes contains imbedded garnets, which form red spots, and add much to its beauty. It is a rare mineral. It occurs at Baireuth in Germany, in Corsica, at Portsoy in Banffshire, in the Shetland Islands, &c. It is generally found along with foliated limestone associated with schistose rocks. The ancient Romans used it for pillars and for many ornamental purposes; and vases, boxes, &c. are still made of it, and much prized. The ancients ascribed to it imaginary medicinal virtues. Marmolite is a scaly, foliated serpentine; Chrysotile is a delicately fibrous variety, with a silky lustre, often met with as veins in ordinary serpentine. Common Serpentine is a rock rather than a mineral. It often occurs in winding irregular veins; hence the name serpentine. It is generally green or red, the colour being sometimes uniform, at other times mottled, spotted, streaked, veined, or clouded. It occurs not only in veins, but forming irregular sheets and masses, and is usually associated with crystalline schists and granitoid eruptive rocks. The mineral serpentine is always a product of the chemical alteration of other minerals; and there is reason to believe that most of the masses of serpentine are highly altered igneous rocks which were rich in olivine or peridote. Many peridotites are proved to have been altered into serpentine. Concerning the origin of some of the serpentines associated with the crystalline schists there is still much uncertainty. Serpents (Lat. serpere, 'to creep'), the more formal and old-fashioned term for all members of the genus Ophidia, more popularly known as Snakes (q.v.), under which heading the general characters and classification of the Ophidians are treated, as also snake-charming. SERPENT-WORSHIP is one of the most ancient and wide-spread forms of primitive religion, and still exists amongst many savage peoples. The characteristic change of skin is easily associated with notions of resurrection and immortality; but serpent as a personification of evil is anything like it does not appear that the familiar notion of the universally spread, although we do find it early in the Apophis-serpent of the Egyptian Hades, represented on mummy-cases, as well as in the wicked Aji Dahaka of the Zoroastrians, which bears so close a relation to the subtle Serpent of Eden. The worship of Moses' brazen serpent in the days of Hezekiah (2 Kings, xviii. 4) shows that the idea was familiar to the Semitic mind. Serpent-worship appears prominently in early Indian Buddhism; we see traces of it in the great serpent which defended the citadel of Athens, fed every month with honey-cakes; in the Roman genius loci, which was usually supposed to assume this form; and in the kindly offices between men and snakes so common in European folk-tales. Among the Zulus certain harmless green or brown snakes which come fearlessly into the houses are thought to be amatongo or ancestors, and may often be identified by some scar or mark such as the man bore in life. Serpents are by many peoples regarded as common incarnations of deities, whether ancestral or other, such as the rattlesnake worshipped in the Natchez temple of the Sun; the serpentsymbol of the healing deity Esculapius, in whose temple huge tame snakes were kept; the Phoenician serpent with its tail in its mouth, perhaps originally a mere mythic world-snake like the Scandinavian Midgard-worm, but in later ages adopted as an emblem of eternity. Nothing in the history of serpent-worship is more remarkable than its Christian revival, or rather survival, among the mystic vagaries of Gnosticism-the Ophites trained their tame snakes to coil themselves round the eucharistic bread. Snake-worship again comes into close touch with the doctrine of Totemism, and we see how the Sanskrit naga ('serpent') has given the name to a race of snake-worshippers who claim descent from ancestral snakes. On no people has the mystery of the serpent (Prov. xxx. 19) weighed more than upon the Red Indians. It has given its name to rivers, like the Kennebec (Algonkin) and the Antietam (Iroquois); among the Dakotas, Shawnees, and Sacs the words for spirit and snake are similar; the Algonquins think the lightning an immense serpent, and the Caribs speak of the god of the thunderstorm as a mighty serpent. The Ojibways dread to kill a rattlesnake, and if they find one in their path they beseech it to go away and spare them and their families; the same worship was found among the Cherokees and many other tribes, as well as in the strange snake-dances practised among the Zuñis. In Mexico many Sculptured images of serpents are found, almost vying in size and splendour with those found in India. The Vaudoux of Hayti (q.v.) is a special case of serpent-worship. See Fergusson's Tree and Serpent Worship (1868); Gubernatis, Zoological Mythology (1874) for its facts; E. B. Tylor's Primitive Culture (1871); also ANIMALWORSHIP, BEAST-FABLES, OPHITES, TOTEM, &c. Oka. SERTORIUS From the mouth of the tube the head of the worm is stretched out into the water, and bears numer. ous exquisitely coloured gills and a stopper or operculum which closes the mouth of the shell when the head is retracted, and seems also to help in respiration. The colour of the gills is in great part due to the blood which is seen through the thin skin. The food consists of minute organic, and especially vegetable, particles, which are wafted into the mouth by the cilia on the gills. The process by which the worm makes its tube of lime is not clearly understood; it is interesting to observe that in situations where the light comes in one definite direction the calcareous tubes point that way. Several species of Serpula are common on British coasts, and large forms of this genus and of nearly related genera are common in warmer seas. Serrano y Dominguez, FRANCISCO, DUKE DE LA TORRE, a Spanish statesman, was born at Anjonilla in Andalusia on 18th September 1810, and pushed himself to the front in the war against the Carlists. Having gained an intimate place in the favour of the dissolute Queen Isabella, he made the most of his influence and played an active part in the dismal political changes of that sovereign's reign, sometimes being in arms against the ministers of the day and sometimes himself holding the highest administrative posts of the kingdom. He was by profession a liberal, and for some years (1854-66) lent faithful support to O'Donnell. On the overthrow of O'Donnell's government by Narvaez Serrano was banished, but returning two years later (in 1868) he defeated the queen's troops, and, having driven her away into France, became the chief ruler (as regent) of Spain until the accession of Amadeus of Savoy (1870). He waged successful war against the Carlists both in 1872 and in 1874. During the greater part of this latter year he was again at the head of the government, until he resigned the power into the hands of Alfonso XII. He was ambassador at Paris in 1883-84, and died at Madrid on 26th November 1885. Serres, OLIVIA. See OLIVE (PRINCESS). Sertorius, QUINTUS, one of the ablest Roman commanders in the later ages of the Republic, was a native of Nursia, in the country of the Sabines. He began his military career in Gaul, and fought Serpukoff, an (105 B.C.) in the disastrous battle on the Rhone in ancient Russian which the Roman proconsul, Q. Servilius Cæpio, town, 57 miles by was defeated by the Cimbri and Teutones, and took rail S. of Moscow, part in the splendid victory at Aquæ Sextiæ or Aix on the Nara, 3 (102 B. C.), where Marius annihilated the same barmiles from its con- barians. On the breaking out of the sanguinary fluence with the struggle between the party of the nobles under It contains Sulla and the popular party headed by Marius a cathedral (1380), (88 B.C.), he espoused the cause of the latter, and is a place of though he could not respect Marius himself. For considerable com- morally Sertorius was much superior to the military mercial and indus- adventurers of his time; and the impression we trial importance, have of him from Plutarch's picturesque biography manufacturing is that of a valiant, resolute, honest, and stubborn chiefly cottons, Roman, such as was commoner in the 3d than in woollens, leather, the 7th century of the Republic. None of the paper, furniture, Marian generals held out so long or so successfully and earthenware. as he against the victorious oligarchy. He fought Pop. (1885) 20,983. in conjunction with Ciuna the battle at the Colline It was formerly a Gate, which placed Rome at the mercy of the fortress protecting Marians. But he took no active part in the bloody Moscow on the massacres that followed; on the contrary, he slew south. 4000 of Marius' cut-throat slaves who had committed the worst excesses. On the return of Sulla from the east (83 B.C.) Sertorius, finding it impossible to act in concert with the other military leaders of his party, went to Spain, where he continued the struggle in an independent fashion. At first he was unable to maintain his ground, and was obliged to put to Serpula, a Serpula contortuplicata (with expanded gills), on the back of an genus of sedentary Öyster-shell. Chatopod worms, living in twisted calcareous tubes fastened to shells and rocks in the sea, or even to other animals, such as crabs. sea. SERTULARIA In the Mediterranean and in Morocco he led an adventurous life, sometimes fighting against the partisans of Sulla, sometimes mixing in the quarrels of native chiefs. But his fame grew, and at length he was invited back to Spain by the Lusitani; and from them and Roman refugees he formed troops who successfully defied the power of Rome for eight years or more. Sulla sent army after army against him commanded by such men as L. Domitius Ahenobarbus, Q. Metellus Pius, and young Pompey; but none of them was a match for him and his methods of guerilla warfare. The contest was at last terminated by the assassination of Sertorius in 72 B.C. The assassins were all Romans, men proscribed by Sulla, who were fighting under Sertorius. The chief of them was Perperna, who was jealous of his chief, and cherished ambitions of his own. Sertorius seems to have aimed at establishing a strong, stable government in Spain: he created a senate of 300 members from amongst the Romans of his party, and founded a school at Osca (Huesca) for the education of the sons of the Spanish chiefs. But jealousies broke out between the Spaniards and the Romans, and the sternness of Sertorius A Sertularian Colony changed to cruelty and tyranny. But when at the height of his power he was regarded with almost superstitious veneration by the Lusitanians, and the feeling was enhanced by the fact that the great commander was constantly followed about by a tame fawn. Sertularia. a common genus of Hydroids, in which the branched horny investment of the plant-like colony forms a sessile cup around each polyp. The polyps are arranged in a double row, and the colony is attached to stones, shells, seaweeds, (natural size). and the like. Among the hydrothecæ or cups surrounding the polyps or nutritive zooid larger pearshaped capsules or gonothecæ occur, within which the reproductive elements are formed from special generative zooids. Unlike many Campanularians and Tubularians, the Sertularian hydroids never liberate medusoid reproductive individuals or zooids. See HYDROZOA, and Hinck's British Hydroid Zoophytes (2 vols. Lond. 1868). Serum. See BLOOD. Serval (Felis Serval), one of the smaller Felidæ, Serval (Felis Serval). a native of South Africa, the Boschkatte, or Bushcat, of the Cape Colony. It is about two feet in length, exclusive of the tail. The serval is a beautiful animal, yellowish with black spots, the lower parts white with black spots. The fur of the serval is in great request, and is known to furriers as that of the Tiger Cat. Servant. See MASTER AND SERVANT. Servetus, MICHAEL, or MIGUEL SERVETO, a Navarre in 1511, though he stated that he was theologian and physician, was born at Tudela in born at Villanova near Lerida, and from about 1535 always styled himself Michael Villanovanus. at Toulouse. His interest in theological discusHis father sent him to study law at Saragossa and sions was awakened whilst he was yet a student, and having gone to Italy (1530) in the company of Quintaña, confessor to Charles V., he passed on from there into Germany, and came into contact with Luther, Ecolampadius, Bucer, and others of the Reformers. But his own views, especially in respect of the Trinity-he denied that there are three Persons in the Trinity and refused to acknowledge the eternity of the Son, and in other respects professed tenets similar to those of Socinus (q.v.)-were in discord both with those of the Reformers and the authoritative teaching of the Roman Catholic Church. The essay in which he propounded his speculations-De Trinitatis Erroribus (1531)-provoked considerable discussion. In 1536 he began to study medicine at Paris, and after a few years of wandering settled down to practise at Vienna (1541). Four or five years later he began to correspond with Calvin, and in spite of Calvin's openly avowed enmity wished to visit him at Geneva. At length, having secretly reprinted (1553) his collection of theological tracts, he was betrayed, and denounced, it is alleged at the instance of Calvin, to the inquisitor at Lyons. He was arrested, but managed to escape from prison; yet rashly venturing into Geneva he was again arrested, and after a trial of more than two months was burned alive (27th October 1553), the day after sentence was pronounced, at Champnel near Geneva. As a scientific inquirer he is best known by a popular book on syrups and by his demonstration of the pulmonary circulation of the blood. See CALVIN; Tollin, Charakterbild Michel Servet's (1876), Das Lehrsystem M. Servet's (3 vols. 1876-78), and other books; Trechsel, Die Protestantischen Antitrinitarier vor F. Socin (1839); Pünjer, De M. Serveti Doctrina (1876); and Willis, Servetus and Calvin (1877), which, however, must be used with very great caution. Servia, a kingdom of the Balkan Peninsula, bounded N. by the Danube, separating it from Hungary, W. by the Drina, separating it from Bosnia, S. by Turkey, and E. by Bulgaria and Roumania, the Danube flowing between Servia and the last named. It is a compact territory, with an area of 18,754 sq. m., measuring 140 miles from east to west by 110 from north to south. The surface is on the whole mountainous. There are, however, few well-defined mountain-chains, except along the frontiers, where also the highest peaks occur-e.g. the Kapaonik Mountains (6382 feet) in the southwest; but there are a great number of isolated mountain peaks and mountain groups, clothed in many parts with fine forests (12 per cent. of the total area) of oak, beech, walnut, chestnut, and other trees, and parted by fertile valleys, which afford excellent pasturage to numerous herds of cattle and sheep. The districts next Bulgaria and Bosnia are more wild and difficult than the central parts, through which passes the principal highway of the country, the valley of the Morava, stretching southsouth-east from the Danube. Servia is essentially an agricultural country. Of the total area 58 per cent. is set apart for cultivation, the principal crops being wheat, maize, and other cereals, and |