Chapter 19

See authorities forCyrenaica, and F. Studniczka,Kyrene, eine alt-griechische Göttin(1890).

(D. G. H.)

CYRIL(c.315-386), bishop of Jerusalem, where he was probably born, was ordained a presbyter in 345, and had the instruction of the catechumens entrusted to him. In 350 he was elevated to the see of Jerusalem, and became deeply involved in the dogmatic controversies of his time. His metropolitan, Acacius of Caesarea, inclined to Arianism, while Cyril strongly espoused the Nicene creed and was, in consequence, deposed for a time. On the death of the emperor Constantine he was restored; but on the accession of Valens, an Arian emperor, he had once more to resign his post till the accession of Theodosius permitted him to return finally in peace in 379. He attended the second oecumenical council held at Constantinople in 381, where he was received with grateful acclamations for his sufferings in defence of orthodoxy. Cyril was even more conspicuous as a pastor than as a controversialist, and this is seen in his one important work—his twenty-three addresses to catechumens delivered inA.D.348. The first eighteen of these were meant for candidates for baptism; they deal with general topics like repentance and faith, and then expound in detail the baptismal creed of the Jerusalem church. The remaining five addresses were spoken to the newly-baptized in Easter week and explain the mysteries and ritual of baptism, confirmation and the Eucharist. These lectures are said to be “the first example of a popular compend of religion,” and are particularly interesting for the insight which they give us both into the creed-forms of the early church and the various ceremonies of initiation constituting baptism in the 4th century. The evidence which Cyril supplies as to theJerusalem use is supplemented by theS. Silviae peregrinatio, dating from about a generation later. Other tracts and homilies have been ascribed to Cyril of Jerusalem, but they are of doubtful genuineness.

Editions.—A. A. Touttée (Paris, 1720); W. C. Reischl and J. Rupp (Munich, 1848-1860); Migne,Patrol. Graeca.xxxiii. Translation:Catecheses(“Oxford Library of Fathers,” vol. ii.). See Herzog-Hauck,Realencyk.(Förster); Delacroix,St C. de Jérus., sa vie et ses œuvres(Paris, 1865).

CYRIL(376-444), bishop of Alexandria, a more distinguished father of the church than his namesake of Jerusalem, was born in 376, and died in 444. Becoming patriarch of Alexandria about 412, he soon made himself known by the violence of his zeal against Jews, pagans and heretics or supposed heretics alike. He had hardly entered upon his office when he closed all the churches of the Novatians and seized their ecclesiastical effects. He assailed the Jewish synagogues with an armed force, drove the Jews in thousands from the city, and exposed their houses and property to pillage. The prefect of Egypt, Orestes, who endeavoured to withstand his furious zeal, was in turn denounced himself, and had difficulty in maintaining his ground against the fury of the Christian multitude. It was during one of the violent commotions kindled by the strifes of these parties in Alexandria that the illustrious Hypatia, famed for her beauty and her eloquent advocacy of the Neo-Platonic philosophy in opposition to Christianity, was murdered. Her murder has been attributed to the direct instigation of the patriarch himself; but this charge is held to be baseless by others, although there can be no doubt that “the perpetrators were officers of his church,” and undoubtedly drew encouragement from his own violent proceedings. Hypatia was a friend of Orestes, and the hostility that existed betwixt the prefect and the patriarch overflowed towards her, and undoubtedly led to her destruction.

But Cyril’s violence was not merely confined to those who might be considered enemies of the church. He inherited from Theophilus, his uncle and predecessor in the see of Alexandria, a strong aversion to John Chrysostom, the noble bishop of Constantinople, and even after his death opposed for a time all attempts to remove the unjust sentence of condemnation which had been passed upon him. Afterwards he so far yielded to remonstrances as to allow the name of Chrysostom to appear in the list of distinguished martyrs and bishops mentioned in the prayers of his church. These names were inserted in what were called “diptychs” (δίπτυχα νεκρῶν), or two-leaved tablets preserved in the churches—a usage which the Greek Church has continued to this day.

Cyril thus represents—though he differs largely from his predecessors—the tendencies dominant at Alexandria in the 5th century, and their antagonism to the Antiochene school. The story of his opposition to Nestorius at the council of Ephesus in 431 is told elsewhere (seeNestorius). He himself incurred the charge of heresy from the oriental bishops. Satisfied, however, with the deprivation and exile of his opponent, he returned to Alexandria in triumph as the great champion of the faith, and thence continued, by the “unscrupulous use of all the means at his command,” the theological strife for years. He was a bitter opponent of the great Antiochene expositor and apologist Theodoret.

Altogether Cyril presents a character not only unamiable, but singularly deficient in the graces of the Christian life. His style of writing is as objectionable as his character and spirit. Yet he takes high rank as a dogmatic theologian, and those who seek precise and rigid definitions of orthodox belief conjoined with tenacity of conviction find him indispensable. In addition to hisTwelve Anathematismsand the defence of the same, he wrote five other books against Nestorius,Thesaurus—a treatise in dialogue form on the Trinity, a bookOn the Right Wayand anotherOn the Incarnation. In other fields—mystical, exegetical and apologetical—he was equally prolific and forceful. He wrote a tract “On worshipping in spirit and in truth” to defend a spiritual interpretation of the Mosaic law, several commentaries, festival-orations, and a reply to the emperor Julian’s attack on the church. His letters are valuable sources to the student of the Nestorian controversy.

Literature.—The collected edition of J. Aubert (Paris, 1638) formed the basis of Migne’s reprint in vols. 68-77 of thePatr. Graec.Many of the writings have been edited separately (see bibliography in Herzog-Hauck). For an account of his career and position in the history of dogma, see A. Harnack, vols. iii. and iv.passim; O. Bardenhewer’sPatrologie(Freiburg, 1894), pp. 335-343; R. L. Ottley’sDoctrine of the Incarnation, ii. 80 ff.; A. Largent’sÉtudes d’hist. ecclés.; St Cyrille d’Alexandrie et le concile d’Éphèse(Paris, 1892). See also Charles Kingsley’s romanceHypatia.

CYRIL(827-869), apostle of the Slavs, amongst whom he worked in conjunction with his elder brother Methodius (q.v.). Tradition says that while in the Khazar country (where he combated Jewish and Mahommedan influence) he found at Kherson the remains of Clement of Rome, which he bore with him wherever he went, finally depositing them at Rome in 867. His name is associated with the invention of the modified (Cyrillic) form of the Greek alphabet, which largely superseded the ancient Slavonic characters.

CYRILLIC,the alphabet used by the Orthodox Slavs. It is modelled on the Greek Liturgical Uncial of the 9th century, and its invention is traditionally, though in all probability wrongly, ascribed to the Greek missionary Cyril (d. 869). For an account of its origin and development, with a table of its letters, see Slavs.

CYRILLUS,Greek jurist of the 5th century, was professor in the ancient law college of Berytus, and one of the founders of the oecumenical school of jurists (τῆς οἰκουμένης διδάσκαλοι) which preceded the succession of Anastasius to the Eastern empire (A.D.491), and paved the way for Justinian’s legislation. His reputation as a teacher of law was very great; and from the fragments of his works which have been preserved it may be inferred that his merit as a teacher consisted in his going direct to the ancient sources of law, and in interpreting the best writers, such as the commentary of Ulpian on the edict and the Responsa Papiniani. He wrote a treatise on definitions (ὑπόμνημα τῶν δεφινίτων), in which, according to a statement of his contemporary Patricius, the subject of contracts was treated with superior precision and great method, and which has supplied the materials for many important scholia appended to the first and second titles of the eleventh book of the Basilica. He is generally styled “the great,” to distinguish him from a more modern jurist of the same name, who lived after the reign of Justinian, and who compiled an epitome of the Digest.

CYRTO-STYLE(Gr.κυρτός, convex, andστῦλος, column), in architecture, a circular projecting portico with columns; like those of the transept entrances of St Paul’s cathedral and the western entrance of St Mary-le-Strand, London.

CYRUS(Gr.Κῦρος; Pers.Kuru-sh; Babyl.Kurash; Hebr.Kōresh), the Latinized form of a Persian name borne by two prominent members of the Achaemenid house.

1.Cyrus the Great, the founder of the Persian empire, was the son of Cambyses I. His family belonged to the clan of the Achaemenidae—in the inscription on the pillars and columns of the palace of Pasargadae (Murghab) he says: “I am Cyrus the king, the Achaemenid”—the principal clan (φρήτρη) of the Persian tribe of the Pasargadae (q.v.). But in his proclamation to the Babylonians (V.R. 35; Sir H. Rawlinson,Journal of the R. Asiat. Soc., n.s., xii., 1880; Schrader,Keilinschriftliche Bibliothek, iii. 2, 120 ff.; Hagen, in Delitzsch and Haupt,Beiträge zur Assyriologie, ii., 1894, where the chronicle of Nabonidus is also published anew with a much improved translation) he calls his ancestors, Teispes, Cyrus I. and Cambyses I., “kings of Anshan,” and the same title is given to him in the inscriptions and in the chronicle of Nabonidus of Babylon before his victory over Astyages. Anshan is a district of Elam or Susiana, the exact position of which is still subject to much discussion. As we know from Jeremiah xlix. 34 ff. (cf. Ezekiel xxxii. 24 ff.) that the Elamites suffered a heavy defeat in 596B.C., it is very probable that the Pasargadian dynast Teispes conquered Anshan in this year. Modern authors have often supposed that Cyrus and his ancestors were in reality Elamites; but thisis contrary to all tradition, and there can be no doubt that Cyrus was a genuine Persian and a true believer in the Zoroastrian religion. In Herodotus vii. 11 the genealogy of Cyrus is given in exactly the same way as in the proclamation of Cyrus himself; Teispes is called here the son of the eponym Achaemenes.

The Pasargadian kings of Anshan were vassals of the Median empire. Their kingdom cannot have been of large extent, as Nabonidus in a contemporary inscription (Cylinder from Abu Habba, VR. 64, Schrader,Keilinschriftl. Bibliothek, iii. 2, 96), where he mentions his rebellion against Astyages, calls Cyrus “king of Anshan, his (i.e.Astyages’) small servant (vassal).” From this inscription we learn that the rebellion of Cyrus (who seems to have become king in 558B.C., as Herod. i. 214 gives him a reign of 29 years) began in 553B.C., and from the annals that in 550 Astyages marched against Cyrus, but was defeated; his troops revolted against him, he was taken prisoner, and Cyrus occupied and plundered Ecbatana. The relation of Ctesias (preserved by Nic. Dam. fr. 66; Anaximenes of Lampsacus in Steph. Byz. s.v.Πασαργάδαι, Strabo xv. p. 729; Polyaen. vii. 6. 1, 9, 45. 2) that Cyrus was three times beaten by Astyages and that the decisive battle took place in the mountains of Pasargadae, is certainly in the main historical although Herodotus (i. 127 ff.) only mentions the treason of the Median general Harpagus and the defeat and captivity of Astyages. In the rebellion the Persian tribes of the Maraphians and Maspians joined the Pasargadae (Herod. i. 125), while the other tribes appear not to have acknowledged Cyrus till after his victory (seePersis). From then he calls himself “king of the Persians.”

The history of Cyrus very soon became involved and quite overgrown with legends. Herodotus (i. 95) tells us that he knew four different traditions about him. One makes him the son of Mandane, a daughter of Astyages (originally evidently by a god), who is exposed in the mountains by his grandfather on account of an oracle, but suckled by a dog (a sacred animal of the Iranians) and educated by a shepherd;i.e.the myth which we know from the stories of Oedipus, Perseus, Telephus, Pelias and Neleus, Romulus, Sargon of Agade, Moses, the Indian hero Krishna, and many others, has been transferred to the founder of the Persian empire. At the same time, the rule of Cyrus and the Persians is legitimated by his family connexion with Astyages. This account is partly preserved in Justin i. 4. 10 (probably from Charon of Lampsacus) and in Aelian,Var. Hist.xiv. 42, and alluded to by Herodotus i. 95 and 122. The second account, which Herodotus follows, is a rationalized version of the first, where the dog is changed into a woman (the wife of the shepherd) named Spako (bitch). In the later part of his story Herodotus is dependent on the family traditions of Harpagus, whose treason is justified by the cruelty with which Astyages had treated him (the story of Atreus and Thyestes is transferred to them). Harpagus afterwards stood in high favour with Cyrus, and commanded the army which subdued the coasts of Asia Minor; his family seems to have been settled in Lycia. In a third version, preserved from Ctesias in Nicolaus Damasc. p. 66 (cf. Dinonap.Athen. xiv. 633 C), Cyrus is the son of a poor Mardian bandit Atradates (the Mardians are a nomadic Persian tribe, Herod. i. 125), who comes as a voluntary slave to the court of Astyages, and finds favour with the king. A Chaldaean sage prophesies to him his future greatness, and another Persian slave, Oebares, becomes his associate. He flies to Persia, evades the pursuers whom Astyages sends after him, and begins the rebellion. After the victory Oebares kills Astyages against the will of Cyrus, and afterwards kills himself to evade the wrath of Cyrus. Parts of this story are preserved also in Strabo xv. p. 729, and Justin i. 6. 1-3; 7. 1; cf. Ctesiasap.Photium 2-7; many traces of it were afterwards transferred to the story of Ardashir I. (q.v.), the founder of the Sassanid empire. With this version Ctesias and Nicolaus have connected another, in which Cyrus is the son of a Persian shepherd who lives at Pasargadae, and fights the decisive battle at this place. The didactic novel of Xenophon, theCyropaedia, is a free invention adapted to the purposes of the author, based upon the account of Herodotus and occasionally influenced by Ctesias, without any independent traditional element. The account of Aeschylus,Pers.765 ff., is a mixture of Greek traditions with a few oriental elements; here the first king is Medos (the Median empire); his nameless son is succeeded by Cyrus, a blessed ruler, beloved by the gods, who gave peace to all his friends and conquered Lydia, Phrygia, Ionia. Then comes his nameless son, then Mardos (i.e.Smerdis, to whom the name of the Mardians is transferred) who is killed by Artaphrenes (i.e.Artaphernes, Herod. iii. 78, one of the associates of Darius), then Maraphis (eponym of the Maraphian tribe), then another Artaphrenes, then Darius.

The principal events of the later history of Cyrus are in the main correctly stated by Herodotus, although his account contains many legendary traditions. The short excerpt from Ctesias, which Photius has preserved, contains useful information, although we must always mistrust him. Of great value are a short notice in the fragments of Berossus and another in the Old Testament. The original sources are very scanty, besides the cylinder containing his proclamation to the Babylonians we possess only a great many dated private documents from Babylon. These serve to fix the chronology, which is here as everywhere quite in accordance with the dates of the canon of Ptolemy.

Soon after the conquest of the Median empire, Cyrus was attacked by a coalition of the other powers of the East, Babylon, Egypt and Lydia, joined by Sparta, the greatest military power of Greece. In the spring of 546 Croesus of Lydia began the attack and advanced into Cappadocia, while the other powers were still gathering their troops. But Cyrus anticipated them; he defeated Croesus and followed him to his capital. In the autumn of 546 Sardis was taken and the Lydian kingdom became a province of the Persians. The famous story of Herodotus, that the conqueror condemned Croesus to the stake, from which he was saved by the intervention of the gods, is quite inconsistent with the Persian religion (seeCroesus).

During the next years the Persian army under Harpagus suppressed a rebellion of the Lydians under Pactyas, and subjugated the Ionian cities, the Carians and the Lycians (when the town Xanthus resisted to the utmost). The king of Cilicia (Syennesis) voluntarily acknowledged the Persian supremacy. Why the war with Babylon, which had become inevitable, was delayed until 539, we do not know. Here too Cyrus in a single campaign destroyed a mighty state. The army of Nabonidus was defeated; Babylon itself attempted no resistance, but surrendered on the 16th Tishri (10th of October) 539, to the Persian general Gobryas (Gaubaruva, see the chronicle of the reign of Nabonidus; the name Gobryas is preserved also by Xenophon,Cyrop.vii. 4. 24); it is possible that the Chaldaean priests, who were hostile to Nabonidus, betrayed the town. In a proclamation issued after his victory Cyrus guarantees life and property to all the inhabitants and designates himself as the favourite of Marduk, the great local god (Bel, Bel-Merodak) of Babel. It is very odd that modern authors have considered this proclamation as inconsistent with the Zoroastrian creed.

From the beginning of 538 Cyrus dates his years as “king of Babylon and king of the countries” (i.e.of the world). With the capital, the Babylonian provinces in Syria fell to the Persians; in 538 Cyrus granted to the Jews, whom Nebuchadrezzar had transported to Babylonia, the return to Palestine and the rebuilding of Jerusalem and its temple (seeJews, § 19). It is probable that Cyrus had fought more than one war against the peoples of eastern Iran; according to Ctesias he had, before the war with Croesus, defeated the Bactrians and the Sacae (in Ferghana; their king Amorges is the eponym of the Amyrgian Sacae, Herod. vii. 64, called by DariusHaumavarkā); and the historians of Alexander mention a march through Gedrosia, where he lost his whole army but seven men (Arrian vi. 24. 2; Strabo xv. 722), a tribe Ariaspae on the Etymandros (in Sijistan), who, on account of the support which they gave him against the Scythians, were called Euergetae (Arrian iii. 27. 4; Diod. xvii. 81; Curt. vii. 3. 1), and a town Cyropolis, founded by himon the Jaxartes (Arrian iv. 2. 3; Curt. vii. 6. 16; Strabo xi. 517, called Cyreskhata by Ptolem. vi. 12. 5). In 530, having appointed his son Cambyses king of Babel, he set out for a new expedition against the East. In this war he was killed (Herod.) or mortally wounded (Ctesias). According to Herodotus he attacked the Massagetae beyond the Jaxartes; according to Ctesias, the Derbices, a very barbarous tribe (cf. Strabo xi. 520; Aelian,Var. Hist.iv. 1) on the border of the Caspian, near the Hyrcanians (Strabo xi. 514; Steph. Byz.; Curt. vii. 2. 7; Dion. Perieg. 734 ff.; Pomp. Mela iii. 5), or on the Oxus (Plin. vi. 48; Ptolem. vi. 10. 2;Tab. Peuting.). Berossus (ap.Euseb.Chron.i. 29) simply says that he fell against the Dahae,i.e.the nomads of the Turanian desert. His death occurred in 528B.C., as we have a Babylonian tablet from the Adar of the tenth year of Cyrus,i.e.February 528; for in Babylon the first year of Cyrus began in the spring of 538.

In his native district Cyrus had built a city with a palace, called after his tribe Pasargadae (now Murghab), and here he was buried (seePasargadae). In a short time he, the petty prince of an almost unknown tribe, had founded a mighty empire, which extended from the Indus and Jaxartes to the Aegaean and the borders of Egypt. This result shows that Cyrus must have been a great warrior and statesman. Nor is his character without nobility. He excels in the humanity with which he treated the vanquished. He destroyed no town nor did he put the captive kings to death; in Babylonia he behaved like a constitutional monarch; by the Persians his memory was cherished as “the father of the people” (Herod. iii. 89), and the Greek tradition preserved by Aeschylus (cf. above) shows that his greatness was acknowledged also by his enemies. He therefore deserves the homage which Xenophon paid to him in choosing him as hero for his didactic novel.

2.Cyrus the Younger, son of Darius II. and Parysatis, was born after the accession of his father in 424. When, after the victories of Alcibiades, Darius II. decided to continue the war against Athens and give strong support to the Spartans, he sent in 408 the young prince into Asia Minor, as satrap of Lydia and Phrygia Major with Cappadocia, and commander of the Persian troops, “which gather into the field of Castolos” (Xen.Hell.i. 4. 3;Anab.i. 9. 7),i.e.of the army of the district of Asia Minor. He gave strenuous support to the Spartans; evidently he had already then formed the design, in which he was supported by his mother, of gaining the throne for himself after the death of his father; he pretended to have stronger claims to it than his elder brother Artaxerxes, who was not born in the purple. For this plan he hoped to gain the assistance of Sparta. In the Spartan general Lysander he found a man who was willing to help him, as Lysander himself hoped to become absolute ruler of Greece by the aid of the Persian prince. So Cyrus put all his means at the disposal of Lysander in the Peloponnesian War, but denied them to his successor Callicratidas; by exerting his influence in Sparta, he brought it about that after the battle of Arginusae Lysander was sent out a second time as the real commander (though under a nominal chief) of the Spartan fleet in 405 (Xen.Hell.ii. 1. 14). At the same time Darius fell ill and called his son to his deathbed; Cyrus handed over all his treasures to Lysander and went to Susa. After the accession of Artaxerxes II. in 404, Tissaphernes denounced the plans of Cyrus against his brother (cf. Plut.Artax.3); but by the intercession of Parysatis he was pardoned and sent back to his satrapy. Meanwhile Lysander had gained the battle of Aegospotami and Sparta was supreme in the Greek world. Cyrus managed very cleverly to gather a large army by beginning a quarrel with Tissaphernes, satrap of Caria, about the Ionian towns; he also pretended to prepare an expedition against the Pisidians, a mountainous tribe in the Taurus, which was never obedient to the Empire. Although the dominant position of Lysander had been broken in 403 by King Pausanias, the Spartan government gave him all the support which was possible without going into open war against the king; it caused a partisan of Lysander, Clearchus, condemned to death on account of atrocious crimes which he had committed as governor of Byzantium, to gather an army of mercenaries on the Thracian Chersonesus, and in Thessaly Menon of Pharsalus, head of a party which was connected with Sparta, collected another army.

In the spring of 401 Cyrus united all his forces and advanced from Sardis, without announcing the object of his expedition. By dexterous management and large promises he overcame the scruples of the Greek troops against the length and danger of the war; a Spartan fleet of thirty-five triremes sent to Cilicia opened the passes of the Amanus into Syria and conveyed to him a Spartan detachment of 700 men under Cheirisophus. The king had only been warned at the last moment by Tissaphernes and gathered an army in all haste; Cyrus advanced into Babylonia, before he met with an enemy. Here ensued, in October 401, the battle of Cunaxa. Cyrus had 10,400 Greek hoplites and 2500 peltasts, and besides an Asiatic army under the command of Ariaeus, for which Xenophon gives the absurd number of 100,000 men; the army of Artaxerxes he puts down at 900,000. These numbers only show that he, although an eyewitness, has no idea of large numbers; in reality the army of Cyrus may at the very utmost have consisted of 30,000, that of Artaxerxes of 40,000 men. Cyrus saw that the decision depended on the fate of the king; he therefore wanted Clearchus, the commander of the Greeks, to take the centre against Artaxerxes. But Clearchus, a tactician of the old school, disobeyed. The left wing of the Persians under Tissaphernes avoided a serious conflict with the Greeks; Cyrus in the centre threw himself upon Artaxerxes, but was slain in a desperate struggle. Afterwards Artaxerxes pretended to have killed the rebel himself, with the result that Parysatis took cruel vengeance upon the slayer of her favourite son. The Persian troops dared not attack the Greeks, but decoyed them into the interior, beyond the Tigris, and tried to annihilate them by treachery. But after their commanders had been taken prisoners the Greeks forced their way to the Black Sea. By this achievement they had demonstrated the internal weakness of the Persian empire and the absolute superiority of the Greek arms.

The history of Cyrus and of the retreat of the Greeks is told by Xenophon in hisAnabasis(where he tries to veil the actual participation of the Spartans). Another account, probably from Sophaenetus of Stymphalus, was used by Ephorus, and is preserved in Diodor. xiv. 19 ff. Further information is contained in the excerpts from Ctesias by Photius; cf. also Plutarch’s life of Artaxerxes. The character of Cyrus is highly praised by the ancients, especially by Xenophon (cf. also hisOeconomics, c. iv.); and certainly he was much superior to his weak brother in energy and as a general and statesman. If he had ascended the throne he might have regenerated the empire for a while, whereas it utterly decayed under the rule of Artaxerxes II. (See alsoPersia:Ancient History.)

(Ed. M.)

CYSTOFLAGELLATA(so named by E. Haeckel), a group of Mastigophorous Protozoa, distinguished from Flagellata by their large size (0.15-1.5 mm.), and their branched endoplasm, recalling that ofTracheliusamong Infusoria, within a firm ectosarc bounded by a strong cuticle. Nutrition is holozoic, a deep groove leading down to a mouth and pharynx. A long fine flagellum arises from the pharynx inNoctiluca(E. Suriray)Leptodiscusand (R. Hertwig); and in the former genus, a second flagellum, thick, long and transversely striated, rises farther out, in the groove; this was likened by E. R. Lankester to a proboscis, whence his name of Rhynchoflagellata, which we discard as unnecessary and posterior to Haeckel’s.Noctilucahas thus the form of an apple with a long stalk.Leptodiscus(R. Hertwig) has the form of a medusa without a proboscis—it is menisciform with the thin contractile margin produced inwards like a velum on the concave side, while the mouth is on the convex surface and the single flagellum springs from a blind tube on the same surface.Craspedotella(C. A. Kofoid), the third genus, is still more medusiform, with a broad velum, and the mouth in a convex central protrusion of the roof of the bell; and a thick flagellum springs from a blind tube on the convex surface. All three genera are pelagic and phosphorescent, this property being seated in the ectoplasm;Noctiluca miliarisis indeed the chief source of the phosphorescence of our summer seas. O. Bütschli, like other writers, regards the Cystoflagellates as closely allied to the Dinoflagellates, the small flagellumcorresponding to the longitudinal, the large flagellum to the transverse flagellum of that group.

1 and 2, Young stages ofNoctiluca miliaris.

a, the big flagellum; the unlettered filament becomes the oral flagellum of the adult.n, nucleus.s, the so-called spine (superficial ridge of the adult).

a, the big flagellum; the unlettered filament becomes the oral flagellum of the adult.

n, nucleus.

s, the so-called spine (superficial ridge of the adult).

3 and 4, Two stages in the fission ofNoctiluca miliaris, Suriray.

n, nucleus.N, food-particles.t, muscular flagellum.

n, nucleus.

N, food-particles.

t, muscular flagellum.

5.Noctiluca miliaris, viewed from the aboral side (after Allman,Quart. Jour. Mic. Sci., 1872).

a, entrance to atrium or flagellar fossa (= longitudinal groove of Dinoflagellata).c, superficial ridge.d, big flagellum (= flagellum of transverse groove of Dinoflagellata).h, nucleus.

a, entrance to atrium or flagellar fossa (= longitudinal groove of Dinoflagellata).

c, superficial ridge.

d, big flagellum (= flagellum of transverse groove of Dinoflagellata).

h, nucleus.

6.Noctiluca miliaris, acted upon by iodine solution, showing the protoplasm shrunk away from the structureless pellicle.

a= entrance to atrium.

7. Lateral view ofNoctiluca miliaris.

a, entrance to atrium.b, atrium.c, superficial ridge.d, big flagellum.e= mouth and gullet, in which is seen Krohn’s oral flagellum (= the chief flagellum, or flagellum of the longitudinal groove of Dinoflagellata).f, broad process of protoplasm extending from the superficial ridgecto the central protoplasm.g, duplicature of pellicle in connexion with superficial ridge.h, nucleus.

a, entrance to atrium.

b, atrium.

c, superficial ridge.

d, big flagellum.

e= mouth and gullet, in which is seen Krohn’s oral flagellum (= the chief flagellum, or flagellum of the longitudinal groove of Dinoflagellata).

f, broad process of protoplasm extending from the superficial ridgecto the central protoplasm.

g, duplicature of pellicle in connexion with superficial ridge.

h, nucleus.

The reproduction ofNoctilucahas been fairly made out; in the adult state it divides by fission down the oral groove; as a preliminary the external differentiations disappear, and the nucleus divides by modified mitosis; then the external organs are regenerated. Under circumstances not well made out, conjugation between two adults takes place by their fusion commencing at the oral region; flagella and pharynx disappear and the nuclei fuse, while the cytoplasts condense into a sphere. The nucleus undergoes broad division, the young nuclei pass to the surface, which becomes imperfectly divided by grooves into as many rounded prominences as there are nuclei (up to 128 or 256); and these become constricted off from the residual useless cytoplasm as zoospores with two unequal flagella, which were at first regarded as Dinoflagellates, of which they have the form (figs. 5, 6). The metamorphosis of these has not yet been observed.

Literature.—E. Suriray,Magazin de zoologie, 1836; G. J. Allman,Quarterly Journal of Microscopic Science, n.s. xii., 1872; L. Cienkowsky, “Zoospore formation in Noctiluca,”Archiv f. mikroskopische Anatomie, vii., 1871; R. Hertwig, “Leptodiscus,”Jenaische Zeitschrift, xi., 1877; C. Ischikawa,Journal of the College of Science(Tokyo, 1894), xii., 1899; F. Doflein, “Conjugation of Noctiluca,”Zoologische Jahrbücher, Anatomie, xiv., 1900; C. A. Kofoid, “Craspedotella,” inBull. Mus. Comp. Zool. Harvard, xlvi., 1905; O. Bütschli, “Mastigophora,” inProtozoa(Braun’s Thierreich, vol. i.,Protozoa) (1883-1887).

(M. Ha.)

CYSTOLITH(Gr.κύστις, cavity, andλίθος, stone), a botanical term for the inorganic concretions, usually of calcium carbonate, formed in a cellulose matrix in special cells, generally in the leaf of plants of certain families,e.g.Ficus elastica, the india-rubber plant.

CYTHERA(mod.Cerigo, but still officially known as Cythera), one of the Ionian islands, situated not less than 150 m. from Zante, but only about 8 m. from Cape Malea on the southern coast of Greece. Its length from N. to S. is nearly 20 m., and its greatest breadth about 12; its area is 114 sq. m. The surface is rocky and broken, but streams abound, and there are various parts of considerable fertility. Two caves, of imposing dimensions, and adorned with stalactites of great beauty, are the most notable among its natural peculiarities; one is situated at the seaward end of the glen of the Mylopotamus, and the other, named Santa Sophia, about two hours’ ride from Capsali (Kapsali). Less of the ground is cultivated and more of it is in pasture land than in any other of the seven islands. Some wine and corn are produced, and the quality of the olive oil is good. The honey is still highly prized, as it was in remote antiquity; and a considerable quantity of cheese is manufactured from the milk of the goat. Salt, flax, cotton and currants are also mentioned among the produce. The people are industrious, and many of them seek employment as labourers in the Morea and Asia Minor. Owing to emigration, the population appears to be steadily diminishing, and is now only about 6000, or less than half what it was in 1857. Unfortunately the island has hardly a regular harbour on any part of the coast; from its situation at the meeting, as it were, of seas, the currents in the neighbourhood are strong, and storms are very frequent. The best anchorage is at San Nicolo, at the middle of the eastern side of the island. The principal village is Capsali, a place of about 1500 inhabitants, at the southern extremity, with a bishop, and several convents and churches; the lesser hamlets are Modari, Potamo and San Nicolo.

There are comparatively few traces of antiquity, and the identification of the ancient cities has been disputed. The capital, which bore the same name as the island, was at Paleo-Kastro, about 3 m. from the present port of Avlemona. In the church of St Kosmas are preserved some of the archaic Doric columns of the famous temple of Aphrodite of Cythera, whose worship had been introduced from Syria, and ultimately spread over Greece. According to the accepted story, it was here that the goddess first landed when she emerged from the sea. At a very early date Cythera was the seat of a Phoenician settlement, established in connexion with the purple fishery of the neighbouring coast; it is said that it was therefore called Porphyris (cf. Pliny iv. 18, 19). For a time dependent on Argos, it became afterwards an important possession of the Spartans, who annually despatched a governor named the Cytherodices. In the Peloponnesian war, Nicias occupied the island, but in 421 it was recovered by Sparta. Its modern history has been very much the same as that of the other Ionian islands; but it was subject to Venice for a much shorter period—from 1717 to 1797.

See the works referred to underCephalonia, and also Weil, inMittheil. d. deutsch. Inst. zu Athen(1880), pp. 224-243.

CYTISINE(Ulexin,Sophorin), C11H14N2O, an alkaloid discovered in 1818 by J. B. Chevreul in the seeds of laburnum (Cytisus Laburnum) and isolated by A. Husemann and W. Marmé in 1865 (Zeit. f. Chemie, 1865, i. p. 161). It is also found in the seeds of furze (Ulex europaeus),Sophora tormentosa, andEuchresta horsfieldii. It is extracted from the seeds by analcoholic solution of acetic acid, and forms large crystals which melt at 153° C., and are easily soluble in water, alcohol and chloroform. It is a secondary and tertiary di-acid base, and is strongly alkaline in its reaction. Hydrogen peroxide oxidizes it to oxycytisine, C11H14N2O2, chromic acid to an acid, C11H9NO3, and potassium permanganate to oxalic acid and ammonia. It acts as a violent poison.

See further, P. C. Plugge,Arch. der Pharm.(1891), 229, p. 48 et seq.; A. Partheil,Ber.(1890), 23, p. 3201,Arch. der Pharm.(1892), 230, p. 448; M. Freund and A. Friedmann,Ber.(1901), 34, p. 615; and J, Herzig and H. Meyer,Monats. f. Chem.(1897), 18, p. 379.

CYTOLOGY(fromκύτος, a hollow vessel, andλόγος, science), the scientific study of the “cells” or living units of protoplasm (q.v.), of which plants and animals are composed. All the higher, and the great majority of the lower, plants and animals are composed of a vast number of these vital units or “cells.” In the case of many microscopic forms, however, the entire organism, plant or animal, consists throughout life of a single cell. Familiar examples of these “unicellular” forms are Bacteria and Diatoms among the plants, and Foraminifera and Infusoria among the animals. In all cases, however, whether the cell-unit lives freely as a unicellular organism or forms an integral part of a multicellular individual, it exhibits in itself all the phenomena characteristic of living things. Each cell assimilates food material, whether this is obtained by its own activity, as in the majority of the protozoa, or is brought, as it were, to its own door by the blood stream, as in the higher Metazoa, and builds this food material into its own substance, a process accompanied by respiration and excretion and resulting in growth. Each cell exhibits in greater or less degree “irritability,” or the power of responding to stimuli; and finally each cell, at some time in its life, is capable of reproduction. It is evident therefore that in the multicellular forms all the complex manifestations of life are but the outcome of the co-ordinated activities of the constituent cells. The latter are indeed, as Virchow has termed them, “vital units.” It is therefore in these vital units that the explanation of vital phenomena must be sought (seePhysiology). As Verworn1said, “It is to the cell that the study of every bodily function sooner or later drives us. In the muscle cell lies the problem of the heart beat and that of muscular contraction; in the gland cell reside the causes of secretion; in the epithelial cell, in the white blood corpuscle, lies the problem of the absorption of food, and the secrets of the mind are hidden in the ganglion cell.” So also the problems of development and inheritance have shown themselves to be cell problems, while the study of disease has produced a “cellular pathology.” The most important problems awaiting solution in biology are cell problems.

Historical.—The cell-theory ranks with the evolution theory in the far-reaching influence it has exerted on the growth of modern biology; and although almost entirely a product of the 19th century, the history of its development gives place, in point of interest, to that of no other general conception. The cell-theory—in a form, however, very different from that in which we now know it—was originally suggested by the study of plant structure; and the first steps to the formulation, many years later, of a definite cell-theory, were made as early as the later part of the 17th century by Robert Hooke, Marcello Malpighi and Nehemiah Grew. Hooke (1665) noted and described the vesicular nature of cork and similar vegetable substances, and designated the cavities by the term “cells.” A few years later Malpighi (1674) and Grew (1682), still of course working with the low power lenses alone available at that time, gave a more detailed description of the finer structure of plant tissue. They showed that it consisted in part of little cell-like cavities, provided with firm cell-walls and filled with fluid, and in part of long tube-like vessels. A long time passed before the next important step forward was made by C. L. Treviranus,2who, working on the growing parts of young plants, showed that the tubes and vessels of Malpighi and Grew arose from cells by the latter becoming elongated and attached end to end, the intervening walls breaking down; a conclusion afterwards confirmed by Hugo von Mohl (1830). It was not, however, until the appearance of Matthias Jakob Schleiden’s paperBeiträge zur Phytogenesis(1838) that we have a really comprehensive treatment of the cell, and the formulation of a definite cell-theory for plants. It is to the wealth of correlated observations and to the philosophic breadth of the conclusions in this paper that the subsequent rapid progress in cytology is undoubtedly to be attributed. Schleiden in this paper attempted to solve the problem of the mode of origin of cells. The nucleus (vide infra) of the cell had already been discovered by Robert Brown (1831), who, however, failed to realize its importance. Schleiden utilized Brown’s discovery, and although his theory of phytogenesis is based on erroneous observations, yet the great importance which he rightly attached to the nucleus as a cell-structure made it possible to extend the cell-theory to animal tissues also. We may indeed date the birth of animal cytology from Schleiden’s short but epoch-making paper. Comparisons between plant and animal tissues had already been made by several workers, among others by Johannes Müller (1835), and by F. G. J. Henle and J. E. Purkinje (1837). But the first real step to a comprehensive cell-theory to include animal tissues was made by Theodor Schwann. This author, stimulated by Schleiden’s work, published in 1830 a series ofMikroskopische Untersuchungen über die Übereinstimmung in der Structur und dem Wachstum der Tiere und Pflanzen. This epoch-making work ranks with that of Schleiden in its stimulating influence on biological research, and in spite of the greater technical difficulties in the way, raised animal cytology at one blow to the position already, and so laboriously, acquired by plant cytology. In the animal cell it is the nucleus and not the cell-wall that is most conspicuous, and it is largely to the importance which Schwann, following the example of Schleiden, attached to this structure as a cell constituent, that the success and far-reaching influence of his work is due. Another feature determining the success of Schwann’s work was his selection of embryonic tissue as material for investigation. He showed that in the embryo the cells all closely resemble one another, only becoming later converted into the tissue elements—nerve cells, muscle cells and so forth—as development proceeded; just as a similar mode of investigation had enabled Treviranus to trace the origin from typical cells of the vascular tissue in plants more than 30 years previously. And just as Treviranus showed that there was a union of cells to form the vessels in plants, so Schwann now showed that a union of cells frequently occurred in the formation of animal tissues.

So great was the stimulus given to cytological research by the work of Schleiden and Schwann that these authors are often referred to as the founders of the cell-theory. Their theory, however, differed very greatly from that of the present time. Not only did they suppose new cells to arise by a sort of “crystallization” from a formative “mother liquor” or “cytoblastema” (vide infra), but they both defined the cell as a “vesicle” provided with a firm cell-wall and with fluid contents. The cell-wall was regarded as the essential cell-structure, which by its own peculiar properties controlled the cell-processes. The work of Schleiden and Schwann marks the close of the first period in the history of the cell-theory—the period dominated by the cell-wall. The subsequent history is marked by the gradual recognition of the importance of the cell-contents. Schleiden had noticed in the plant cell a finely granular substance which he termed “plant slime” (Pflanzenschleim). In 1846 Hugo von Mohl applied to this substance the term “protoplasm”; a term already used by Purkinje six years previously for the formative substance of young animal embryos. Mohl showed that the young plant cell was at first completely filled by the protoplasm, and that only later, by the gradual accumulation of vacuoles in the interior, did this substance come to form a thin layer on the inner surface of the cell-wall. Mohl also described the spontaneous movement of the protoplasm, a phenomenon already noted by Schleiden for his plant slime, and originally discovered by Bonaventura Corti in 1772 for the cells ofChara, and rediscovered in 1807by Treviranus. Not only was attention thus gradually directed to the importance of the cell-contents, but observations were not lacking, even in the plant kingdom, tending to weaken the importance hitherto attached to the cell-wall. Among these may be mentioned Cohn’s observation that in the reproduction of Algal forms the protoplasm contracts away from the cell-wall and escapes as a naked “swarm spore.” Similarly in the animal kingdom instances began to be noted in which no membrane appeared to be present (Kolliker, 1845; Bischoff, 1842), and for some time it was hotly debated whether these structures could be regarded as true cells. As a result of the resemblance between the streaming movements in these apparently naked cells (e.g.lymphocytes) and those seen in plant cells, R. Remak was led (1852-1853) to apply Mohl’s term “protoplasm” to the substance of these animal cells also. Similarly Max Schultze (1863) and H. A. de Bary (1859), as a result of the study of unicellular animals, came to the conclusion that the substance of these organisms, originally termed “Sarcode” by F. Dujardin, was identical with that of the plant and animal cell. Numerous workers now began to realize the subordinate position of the cell-wall (e.g.Nägeli, Alexander Braun, Leydig, Kolliker, Cohn, de Bary, &c.), but it is to Max Schultze above all that the credit is due for having laid the foundation of the modern conception of the cell—a conception often referred to as theproto-plasmic-theoryin opposition to thecell-theory of Schleiden and Schwann. Max Schultze showed that one and the same substance, protoplasm, occurred in unicellular forms and in the higher plants and animals; that in plants this substance, though usually enclosedwithina cell membrane, was sometimes naked (e.g.swarm spores), while in many animal tissues and in many of the unicellular forms the cell-membrane was always absent. He therefore concluded that in all cases the cell-membrane was unessential, and he redefined the “cell” of Schleiden and Schwann as “a small mass of protoplasm endowed with the attributes of life” (1861). In the same year the physiologist Brücke maintained that the complexity of vital phenomena necessitated the assumption for the cell-protoplasm itself of a complex structure, only invisible because of the limitations of our methods of observation. The cell in fact was to be regarded as being itself an “elementary organism.” By this time too it was realized that the formation of cellsde novo, postulated by Schleiden’s theory of “phytogenesis,” did not occur. Cells only arose by the division of pre-existing cells,—as Virchow neatly expressed it in his since famous aphorism,omnis cellula e cellula. It was, however, many years before the details of this “cell-division” were laid bare (seeCell-Divisionbelow).

General Morphology of the Cell.—In its simplest form the cell is a more or less spherical mass of viscid, translucent and granular protoplasm. In addition to the living protoplasm there is present in the cell food-material in various stages of assimilation, which usually presents the appearance of fine granules or spherules suspended in the more or less alveolar or reticular mesh-work of the living protoplasm. In addition there may be more or less obvious accumulations of waste material, pigment, oil drops, &c.—products of the cell’s metabolic activity. All these relatively passive inclusions3are distinguished from the living protoplasm by the term “metaplasm” (Hanstein), or “paraplasm” (Kupffer), although in practice no very sharp distinction can be drawn between them. The cell is frequently, but by no means always, bounded by a cell-wall of greater or less thickness. In plants this cell-wall consists of cellulose, a substance closely allied to starch; in animals only very rarely is this the case. Usually the cell-wall, when this is present, is a product of the cell’s secretive activity; sometimes, however, it appears to be formed by an actual conversion of the surface layer of the protoplasm, and retains the power of growth by “intussusception” like the rest of the protoplasm. Even when a limiting membrane is present, however, evidence is steadily accumulating to show that the cell is not an isolated physiological unit, but that, in the vast majority of cases, there is a protoplasmic continuity between the cells of the organism. This continuity, which is effected by fine protoplasmic threads (“cell-bridges”) piercing the cell-wall and bridging the intercellular spaces when these are present, is to be regarded as the morphological expression of the physiological interdependence of the various—often widely separated—tissues of the body.4It is probable that it is the specialization of this primitive condition which has produced the cell-elements of the nervous system. In many cases the cell-connexions are so extensive as to obliterate cell-boundaries. A good example of such a “syncytial” tissue is provided by the heart muscle of Vertebrates and the intestinal musculature of Insects (Webber).5

In all multicellular, and in the great majority of unicellular, organisms the protoplasm of the cell-unit is differentiated into two very distinct regions,—a more or less central region, thenucleus, and a peripheral region (usually much more extensive), the cell-body orcytoplasm. This universal morphological differentiation of the cell-protoplasm is accompanied by corresponding chemical differences, and is the expression of a physiological division of labour of fundamental importance. In some of the simpler unicellular organisms,e.g.Tetramitus, the differentiated protoplasm is not segregated. Such forms are said to have a “distributed” nucleus, and among the Protozoa correspond to Haeckel’s “Protista.” It is probable that among plants the Bacteria and Cyanophyceae have a similar distributed nucleus. In all the higher forms, however, the segregation is well marked, and a “nuclear membrane” separates the substance of the nucleus, or “karyoplasm”6from the surrounding “cytoplasm.” Within the nuclear membrane the karyoplasm is differentiated into two very distinct portions, a clear fluid portion, the “karyolymph,” and a firmer portion in the form of a coarser or finer “nuclear reticulum.” This latter is again composed of two parts, the “linin reticulum,”7and, embedded in the latter and often irregularly aggregated at its nodal points, a granular substance, the “chromatin,”8the latter being the essential constituent of the nucleus. In addition to the chromatin there may be present in the nucleus one or more, usually spherical, and as yet somewhat enigmatical bodies, the “nucleoli.” In addition to the nucleus and cytoplasm, a third body, the “centrosome,” has often been considered as a constant cell-structure. It is a minute granule, usually lying in the cytoplasm not far from the nucleus, and plays an important part in cell-division and fertilization (see below).

Cell-differentiation.—Both among unicellular and multicellular individuals the cell assumes the most varied forms and performs the most diverse functions. In all cases, however, whether we examine the free-living shapeless and slowly creepingAmoeba, or the striped muscle cell or spermatozoon of the Metazoa (fig. 1,bandc), the constant recurrence of cytoplasm and nucleus show that we have to deal in each case with a cell. The variation in the form and structure of the cell is an expression of that universal economic law of nature, “division of labour,” with its almost invariable accompanying “morphological differentiation”; the earliest and most fundamental example being in the differentiation of the cell-protoplasm into cytoplasm and nucleus. In multicellular individuals the division of labour to which the structural complexity of the organism is due is between the individual cell-units, some cells developing oneaspect, some another, of their vital attributes. Thus one cell specializes in, say, secretion, another in contractility, another in receiving and carrying stimuli, and so forth, so that we have the gland cell, the muscle cell, and the nerve cell, each appropriately grouped with its fellows to constitute the particular tissue or organ—gland, muscle or brain—which has for its function that of its constituent cells. In unicellular animals we also find division of labour and its accompanying morphological differentiation, but here there is no subdivision of the protoplasm of the organism into the semi-autonomous units which so greatly facilitate division of labour in the Metazoa; instead, division of labour must be between different regions of protoplasm in the single cell. The sharply defined character of this regional differentiation in the Protozoa, and the surprising structural complexity it may produce, sufficiently clearly show that although multicellular structure has greatly facilitated regional differentiation in the Metazoa, it is by no means essential to this process (see below,Present Position of the Cell-theory).

It is not within the scope of this article to attempt a comprehensive review of the variety in structural complexity to which this division of labour among the cells of the Metazoan and the regional differentiation of the cell-bodies of the Protozoa has given rise. Some indication of the wealth of variety may be best given by taking a general survey of cell-modifications, grouped according to the cell-attributes the expression of which they facilitate.

(a)Structural Complexity facilitating Movement.—One of the most striking, and hence earliest described, of the fundamental attributes of protoplasm is its power of spontaneous movement. This is seen in the walled cell of plant tissue and in the naked cell-body ofAmoeba. In the latter case the streaming movements of the naked protoplasm are accompanied by the formation of “pseudopodia,” and result in the highly characteristic “amoeboid” creeping movement of this and similar organisms (e.g.lymph corpuscles of the blood).9In these examples the whole protoplasm participates in the movement,—there has been no division of labour, and there is, therefore, no visible morphological differentiation. In many cells, movement (either of the entire body or of the surrounding medium) is by means of slender whip-like processes of the protoplasm flagella or cilia. These represent modified pseudopodia, and in the formation of the motile gametes of some of the lower forms,e.g.Myxomycetes (de Bary, 1859), Rhizopods (R. Hertwig, 1874), &c., the actual conversion of a pseudopodium into a flagellum can be witnessed. These vibratile processes may be either one or few in number, and are then large in size and move independently of one another; or they may be very numerous, covering the free surface of the cell (fig. 2,a); they are then very small and move strictly in unison. In the former case they are termed “flagella,” in the latter “cilia.” In some cases the flagellum is accompanied by an undulating membrane (e.g.Trypanosoma among the protozoa and in many spermatozoa), and it may be situated either at the front end (Euglena) or hind end (spermatozoa) of the body during motion. The cilia may form a uniform coating to the free surface of the cell, as in ciliated epithelium (fig. 2,a) and many infusoria, or the cilia may be variously modified and restricted to special regions of the body,e.g.the “undulating membrane” of the peristomial region in many infusoria, the swimming combs of the Ctenophora (q.v.), and the flame cells of the Platyelmia (q.v.). In one group of infusoria (Hypotricha), the cilia, “cirri,” have attained a high degree of differentiation, and reach a considerable size. Both cilia and flagella spring directly from the cell-protoplasm, piercing the cell-membrane, when this is present. At the point where they become continuous with the cell-body there is usually a deeply staining “basal granule.” In some cases the flagella are in direct connexion with the centrosome (see below,Cell-division),e.g.Trypanosoma and spermatozoa, in some cases even while the centrosome is functioning in mitosis (e.g.insect spermatogenesis, Henneguy10and Meves11(fig. 3).

In the ability ofAmoebato contract into a spherical mass, and in the presence in its protoplasm of the contractile vacuole, we see another type of spontaneous movement—contractility—of the protoplasm. In the “musculo-epithelial” cells ofHydra, the elongated basal portion of the cell alone possesses this contractility. In the higher Metazoa the whole cell—muscle cell—is specialized for contractility, and shows, as a result of its specialization, a distinct fibrillation. This fibrillation is foreshadowed in the contractile regions of many Protozoa,e.g.in the cirri of hypotrichous Infusoria, the tentacle ofNoctiluca, and the myophane layer of Gregarines. In the quickly contracting muscle cell of Vertebrates and insects, further specialization has produced a structure of considerable complexity (fig. 1,b). Here also the cell is fibrillated, but the fibrillae (sarcostyles) are much more distinct, and are segmented in a manner which gives to the entire cell a “cross striated” appearance. Since quick movement is usually (but not always) associated with voluntary control, these striated muscle cells are often termed “voluntary” muscle fibres. The great increase in length of these cells is accompanied by the fragmentation of the originally single nucleus.

(b)Cell-modification in Relation to Secretion.—Just as the complex movements considered above were the result of a great development of the power of spontaneous movement possessed by all protoplasm, so cell-secretion is the result of a development of the metabolic processes underlying all vital phenomena. But whereas specialization of the protoplasm for movement resulted in a very obvious morphological complexity, specialization for secretion results in molecular complexity, and only rarely and indirectly results in morphological differentiation. Usually indeed the specialization is only rendered evident by the appearance of the formed secretion,e.g.mucus-secreting epithelial cells (fig. 2,b), the ovarian ovum and the fat cell (fig. 1,a). In some cases a distinct fibrillation of the cytoplasm accompanies or precedes the appearance of the cell-secretion (Mathews, pancreas cell of Amphibia). In many cases the internal secretion is no mere accumulation,e.g.the internal skeleton of the Radiolaria, and the nematocysts of the Coelentera. Frequently in animal tissues the cell-secretions are accumulated in the intercellular spaces, and result in the formation of the various “connective tissues,” all of which are characterized by the immense amount of intercellular substance,e.g.fibrous tissue, cartilage and bone. Cell-modifications facilitating the general metabolism, but not necessarily indicating specialized secretion, also occur,e.g.the “gullet” of many Protozoa, the suctorial tubules of the Acinetaria, and the “nutritive processes” of the ovarian ova in many Lepidoptera. Mention may be made here of the network or canal system of the cytoplasm, described for many cells by Golgi, Holgren and others. An enigmatical structure, the “yolk-nucleus” of many ova, has been frequently regarded as a structure of considerable metabolic importance,e.g.Bambeke (1898) forPholcus.12

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