CHAERONEIA, or Chaeronea, an ancient town of Boeotia, said by some to be the Homeric Arne, situated about 7 m. W. of Orchomenus. Until the 4th century B.C. it was a dependency of Orchomenus, and at all times it played but a subordinate part in Boeotian politics. Its importance lay in its strategic position near the head of the defile which presents the last serious obstacle to an invader in central Greece. Two great battles were fought on this site in antiquity. In 338 B.C. Philip II. and Alexander of Macedon were confronted by a confederate host from central Greece and Peloponnese under the leadership of Thebes and Athens, which here made the last stand on behalf of Greek liberty. A hard-fought conflict, in which the Greek infantry displayed admirable firmness, was decided in favour of Philip through the superior organization of his army. In 86 B.C. the Roman general L. Cornelius Sulla defeated the army of Mithradates VI., king of Pontus, near Chaeroneia. The latter’s enormous numerical superiority was neutralized by Sulla’s judicious choice of ground and the steadiness of his legionaries; the Asiatics after the failure of their attack were worn down and almost annihilated. Chaeroneia is also notable as the birthplace of Plutarch, who returned to his native town in old age, and was held in honour by its citizens for many successive generations. Pausanias (ix. 40) mentions the divine honours accorded at Chaeroneia to the sceptre of Agamemnon, the work of Hephaestus (cf. Iliad, ii. 101). The site of the town is partly occupied by the village of Kapraena; the ancient citadel was known as the Petrachus, and there is a theatre cut in the rock. A colossal seated lion a little to the S.E. of the site marks the grave of the Boeotians who fell fighting against Philip; this lion was found broken to pieces; the tradition that it was blown up by Odysseus Androutsos is incorrect (see Murray, Handbook for Greece, ed. 5, 1884, p. 409). It has now been restored and re-erected (1905).
Authorities.—Thucydides iv. 76; Diodorus xvi. 85-86; Plutarch, Alexander, ch. 9; Sulla, chs. 16-19; Appian, Mithradatica, chs. 42-45; W.M. Leake, Travels in Northern Greece (London, 1835), ii. 112-117, 192-201; B.V. Head, Historia Numorum (Oxford, 1887), p. 292; J. Kromayer, Antike Schlachtfelder in Griechenland (Berlin, 1903), pp. 127-195; G. Sotiriades in Athen. Mitteil. 1903, pp. 301 ff.; 1905, p. 120; 1906, p. 396; Έφημ. Άρχαιολ., 1908, p. 65.
| Spadella cephaloptera (Busch). |
| St, Septa dividing body-cavity transversely. g², Cerebral ganglia. n¹, Commissure uniting this with ventral ganglion (not shown in fig.). n², Nerve uniting cerebral ganglia with small ganglia on head. nr, Olfactory nerve. d, Alimentary canal. r, Olfactory organ. te, Tentacle. t, Tactile hairs springing from surface of body. e, Ovary. el, Oviduct. ho, Testes. sg, Vas deferens. f², f³, Lateral and caudal fins. sb, Seminal pouch. |
| The eyes are indicated as black dots behind the cerebral ganglia. |
CHAETOGNATHA, the name given by R. Leuckhart to a small group of transparent and for the most part pelagic organisms, whose position in the animal kingdom is a very isolated one. Only three genera, Sagitta, Spadella and Krohnia, are recognised, and the number of species is small. Nevertheless these animals exist in extraordinary quantities, so that at certain seasons and under certain conditions the surface of the sea seems almost stiff with the incredible multitude of organisms which pervade it. Rough seas, &c., cause them to seek safety in dropping into deeper water. Deep-sea forms also occur, but in spite of this the group is essentially pelagic.
As a rule the body is some 1 to 2 or 3 cm. in length, though some species are larger, by 4 or 5 mm. in breadth, and it is shaped something like a torpedo with side flanges and a slightly swollen, rounded head. It can be divided into three regions—(i.) head, (ii.) trunk, and (iii.) tail, separated from one another by two transverse septa. The almost spherical head is covered by a hood which can be retracted; it bears upon its side a number of sickle-shaped, chitinous hooks and one or more short rows of low spines—both of these features are used in characterizing the various species. A pair of eyes lie dorsally and behind them is a closed circlet, often pulled out into various shapes, of modified epidermis, to which an olfactory function has been attributed. The interior of the head is filled up with masses of muscle fibres which are mainly occupied with moving the sickle-shaped hooks. The trunk contains a spacious body-cavity filled during the breeding season by the swollen ovaries, and the same is true of the tail if we substitute testes for ovaries.
The skin consists of a transparent cuticle excreted by the underlying ectoderm, the cells of which though usually one-layered may be heaped up into several layers in the head; beneath this is a basement membrane, and then a layer of longitudinal muscle fibres which are limited inside by a layer of peritoneal cells. The muscles are striated and arranged in four quadrants, two dorso-lateral and two ventro-lateral, an arrangement which recalls that of the Nematoda, whilst in their histology they somewhat resemble the muscles of the Oligochaeta. Along each side of the body stretches a horizontal fin and a similar flange surrounds the tail. Into these fins, which are largely cuticular and strengthened by radiating bars, a single layer of ectoderm cells projects.
The mouth, a longitudinal slit, opens on to the ventral surface of the head. It leads into a straight alimentary canal whose walls consist of a layer of ciliated cells ensheathed in a thin layer of peritoneal cells. There is no armature, and no glands, and the whole tract can only be divided into an oesophagus and an intestine. The latter runs with no twists or coils straight to the anus, which is situated at the junction of the trunk with the tail. A median mesentery running dorso-ventrally supports the alimentary canal and is continued behind it into the tail, thus dividing the body cavity into two lateral halves.
There are no specialized circulatory, respiratory or excretory organs.