Turbellaria, that is to say, from diploblastic to triploblastic Metazoa. By themselves they would present no very weighty argument for this line of descent from two-layered to three-layered forms, but the coincidences which occur in the development of Ctenophora and Turbellaria,—the methods of segmentation and gastrulation, of the separation of the mesoblast cells, and of mesenchyme formation,—together with the marked similarity of the adult mesenchyme in the two groups, have led many to accept this pedigree. In his Monograph on the Polyclad Turbellaria of the Bay of Naples, A. Lang regards a Turbellarian, so to say, as a Ctenophora, in which the sensory pole has rotated forwards in the sagittal plane through 90° as regards the original oral-aboral axis, a rotation which actually occurs in the development of Thysanozoon (Müller’s larva); and he sees, in the eight lappets of the preoral ciliated ring of such a larva, the rudiments of the costal plates. According to his view, a simple early Turbellarian larva, such as that of Stylochus, most nearly represents for us to-day that ancestor from which Ctenophora and Turbellaria are alike derived. For details of this brilliant theory, the reader is referred to the original monograph.
Literature.—G. C. Bourne, “The Ctenophora,” in Ray Lankester’s Treatise on Zoology (1900), where a bibliography is given; G. Curreri, “Osservazioni sui ctenofori,” Boll. Soc. Zool. Ital. (2), i. pp. 190-193 et ii. pp. 58-76; A. Garbe, “Untersuchungen über die Entstehung der Geschlechtsorgane bei den Ctenophoren.,” Zeitschr. Wiss. Zool. lxix. pp. 472-491; K. C. Schneider, Lehrbuch der vergleich. Histologie (1902). (G. H. Fo.)
CTESIAS, of Cnidus in Caria, Greek physician and historian,
flourished in the 5th century B.C. In early life he was physician
to Artaxerxes Mnemon, whom he accompanied (401) on his
expedition against his brother Cyrus the Younger. Ctesias was
the author of treatises on rivers, and on the Persian revenues,
of an account of India (which is of value as recording the beliefs
of the Persians about India), and of a history of Assyria and
Persia in 23 books, called Persica, written in opposition to
Herodotus in the Ionic dialect, and professedly founded on the
Persian royal archives. The first six books treated of the history
of Assyria and Babylon to the foundation of the Persian empire;
the remaining seventeen went down to the year 398. Of the
two histories we possess abridgments by Photius, and fragments
are preserved in Athenaeus, Plutarch and especially Diodorus
Siculus, whose second book is mainly from Ctesias. As to the
worth of the Persica there has been much controversy, both in
ancient and modern times. Being based upon Persian authorities,
it was naturally looked upon with suspicion by the Greeks and
censured as untrustworthy.
For an estimate of Ctesias as a historian see G. Rawlinson’s Herodotus, i. 71-74; also the edition of the fragments of the Persica by J. Gilmore (1888, with introduction and notes and list of authorities).
CTESIPHON, a large village on the left bank of the Tigris, opposite to Seleucia, of which it formed a suburb, about 25 m. below Bagdad. It is first mentioned in the year 220 by Polybius v. 45. 4. When the Parthian Arsacids had conquered the lands east of the Euphrates in 129 B.C., they established their winter residence in Ctesiphon. They dared not stay in Seleucia, as this city, the most populous town of western Asia, always maintained her Greek self-government and a strong feeling of independence, which made her incline to the west whenever a Roman army attacked the Parthians. The Arsacids also were afraid of destroying the wealth and commerce of Seleucia, if they entered it with their large retinue of barbarian officials and soldiers (Strabo xvi. 743, Plin. vi. 122, cf. Joseph. Ant. xviii. 9, 2). From this time Ctesiphon increased in size, and many splendid buildings rose; it had the outward appearance of a large town, although it was by its constitution only a village. From A.D. 36-43 Seleucia was in rebellion against the Parthians till at last it was forced by King Vardanes to yield. It is very probable that Vardanes now tried to put Ctesiphon in its place; therefore he is called founder of Ctesiphon by Ammianus Marcellinus (xxiii. 6. 23), where King Pacorus (78-110) is said to have increased its inhabitants and built its walls. Seleucia was destroyed by the Romans in A.D. 164. When Ardashir I. founded the Sassanian empire (226), and fixed his residence at Ctesiphon, he built up Seleucia again under the name of Veh-Ardashir. Later kings added other suburbs; Chosroes I. in 540 established the inhabitants of Antiochia in Syria, whom he had led into captivity, in a new city, “Chosrau-Antioch” (or “the Roman city”) near his residence. Therefore the Arabs designate the whole complex of towns which lay together around Seleucia and Ctesiphon and formed the residence of the Sassanids by the name Madāin, “the cities,”—their number is often given as seven. In the wars between the Roman and Persian empires, Ctesiphon was more than once besieged and plundered, thus by Odaenathus in 261, and by Carus in 283; Julian in 363 advanced to Ctesiphon, but was not able to take it (Ammianus xxiv. 7). After the battle of Kadisiya (Qādisīya) Ctesiphon and the neighbouring towns were taken and plundered by the Arabs in 637, who brought home an immense amount of booty (see Caliphate). From then, these towns decayed before the increasing prosperity of the new Arab capitals Basra and Bagdad. The site is marked only by the ruins of one gigantic building of brick-work, called Takhti Khesra, “throne of Khosrau” (i.e. Chosroes). It is a great vaulted hall ornamented with pilasters, the remainder of the palace and the most splendid example of Sassanian architecture (see Architecture, vol. ii. p. 558, for further details and illustration). (Ed. M.)
CUBA (the aboriginal name), a republic, the largest and most
populous of the West India Islands, included between the
meridians of 74° 7′ and 84° 57′ W. longitude and (roughly) the
parallels of 19° 48′ and 23° 13′ N. latitude. It divides the entrance
to the Gulf of Mexico into two passages of nearly equal
width,—the Strait of Florida, about 110 m. wide between Capes
Hicacos in Cuba and Arenas in Florida (Key West being a little
over 100 m. from Havana); and the Yucatan Channel, about
130 m. wide between Capes San Antonio and Catoche. On the
N.E., E. and S.E., narrower channels separate it from the
Bahamas, Haiti (50 m.) and Jamaica (85 m.). In 1908, by the
opening of a railway along the Florida Keys, the time of passage
by water between Cuba and the United States was reduced to a
few hours.
The island is long and narrow, somewhat in the form of an irregular crescent, convex toward the N. It has a decided pitch to the S. Its length from Cape Maisí to Cape San Antonio along a medial line is about 730 m.; its breadth, which averages about 50 m., ranges from a maximum of 160 m. to a minimum of about 22 m. The total area is estimated at 41,634 sq. m. without the surrounding keys and the Isle of Pines (area about 1180 sq. m.), and including these is approximately 44,164. The geography of the island is still very imperfectly known, and all figures are approximate only. The coast line, including larger bays, but excluding reefs, islets, keys and all minute sinuosities, is about 2500 m. in length. The N. littoral is characterized by bluffs, which grow higher and higher toward the east, rising to 600 ft. at Cape Maisí. They are marked by distinct terraces. The southern coast near Cape Maisí is low and sandy. From Guantánamo to Santiago it rises in high escarpments, and W. of Santiago, where the Sierra Maestra runs close to the sea, there is a very high abrupt shore. To the W. of Manzanillo it sinks again, and throughout most of the remaining distance to Cape San Antonio is low, with a sandy or marshy littoral; at places sand hills fringe the shore; near Trinidad there are hills of considerable height; and the coast becomes high and rugged W. of Point Fisga, in the province of Pinar del Rio. On both the N. and the S. side of the island there are long chains of islets and reefs and coral keys (of which it is estimated there are 1300), which limit access to probably half of the coast, and on the N. render navigation difficult and dangerous. On the S. they are covered with mangroves. A large part of the southern littoral is subject to overflow, and much more of it is permanently marshy. The Zapata Swamp near Cienfuegos is 600 sq. m. in area; other large swamps are the Majaguillar, E. of Cárdenas, and the Ciénaga del Buey, S. of the Cauto river. The Isle of Pines in its northern part is hilly and wooded; in its southern part, very low, level and rather barren; a tidal swamp almost cuts the island in two.
