Chapter 9

See theMemoirs of the Geological Survey, “Geology of the Weald” (1875), “Geology of the Isle of Wight” (2nd ed., 1889), “Geology of the Isle of Purbeck” (1898); and theRecord of Excursions, Geologists’ Association (London, 1891).

(J. A. H.)

GREENSBORO,a city and the county-seat of Guilford county, North Carolina, U.S.A., about 80 m. N.W. of Raleigh. Pop. (1890) 3317, (1900) 10,035, of whom 4086 were negroes; (1910 census), 15,895. Greensboro is served by several lines of the Southern railway. It is situated in the Piedmont region of the state and has an excellent climate. The city is the seat of the State Normal and Industrial College (1892) for girls; of the Greensboro Female College (Methodist Episcopal, South; chartered in 1838 and opened in 1846), of which the Rev. Charles F. Deems was president in 1850-1854, and which, owing to the burning of its buildings, was suspended from 1863 to 1874; and of two institutions for negroes—a State Agricultural and Mechanical College, and Bennett College (Methodist Episcopal, co-educational, 1873). Another school for negroes, Immanuel Lutheran College (Evangelical Lutheran, co-educational), was opened at Concord, N.C., in 1903, was removed to Greensboro in 1905, and in 1907 was established at Lutherville, E. of Greensboro. About 6 m. W. of Greensboro is Guilford College (co-educational; Friends), founded as “New Garden Boarding School” in 1837 and rechartered under its present name in 1888. Greensboro has a Carnegie library, St Leo hospital and a large auditorium. It is the shipping-point for an agricultural, lumbering and trucking region, among whose products Indian corn, tobacco and cotton are especially important; is an important insurance centre; has a large wholesale trade; and has various manufactures, including cotton goods1(especially blue denim), tobacco and cigars, lumber, furniture, sash, doors and blinds, machinery, foundry products and terra-cotta. The value of the factory products increased from $925,411 in 1900 to $1,828,837 in 1905, or 97.6%. The municipality owns and operates the water-works. Greensboro was named in honour of General Nathanael Greene, who on the 15th of March 1781 fought with Cornwallis the battle of Guilford Court House, about 6 m. N.W. of the city, where there is now a Battle-Ground Park of 100 acres (including Lake Wilfong); this park contains a Revolutionary museum, and twenty-nine monuments, including a Colonial Column, an arch (1906) in memory of Brig.-General Francis Nash (1720-1777), of North Carolina, who died in October 1777 of wounds received at Germantown, and Davidson Arch (1905), in honour of William Lee Davidson (1746-1781), a brigadier-general of North Carolina troops, who was killed at Catawba and in whose honour Davidson College, at Davidson, N.C., was named. Greensboro was founded and became the county-seat in 1808, was organized as a town in 1829, and was first chartered as a city in 1870.

1One of the first cotton mills in the South and probably the first in this state was established at Greensboro in 1832. It closed about 20 years afterwards, and in 1889 new mills were built. Three very large mills were built in the decade after 1895, and three mill villages, Proximity, Revolution and White Oak, named from these three mills, lie immediately N. of the city; in 1908 their population was estimated at 8000. The owners of these mills maintain schools for the children of operatives and carry on “welfare work” in these villages.

GREENSBURG,a borough and the county-seat of Westmoreland county, Pennsylvania, U.S.A., 31 m. E.S.E. of Pittsburg. Pop. (1890) 4202; (1900) 6508 (484 foreign-born); (1910) 5420. It is served by two lines of the Pennsylvania railway. It is an important coal centre, and manufactures engines, iron and brass goods, flour, lumber and bricks. In addition to its public school system, it has several private schools, including St Mary’s Academy and St Joseph’s Academy, both Roman Catholic. About 3 m. N.E. of what is now Greensburg stood the village of Hanna’s Town, settled about 1770 and almost completely destroyed by the Indians on the 13th of July 1782; here what is said to have been the first court held west of the Alleghanies opened on the 6th of April 1773, and the county courts continued to be held here until 1787. Greensburg was settled in 1784-1785, immediately after the opening of the state road, not far from the trail followed by General John Forbes on his march to Fort Duquesne in 1758; it was made the county-seat in 1787, and was incorporated in 1799. In 1905 the boroughs of Ludwick (pop. in 1900, 901), East Greensburg (1050), and South-east Greensburg (620) were merged with Greensburg.

See John N. Boucher’sHistory of Westmoreland County, Pa.(3 vols., New York, 1906).

GREENSHANK,one of the largest of the birds commonly known as sandpipers, theTotanus glottisof most ornithological writers. Some exercise of the imagination is however needed to see in the dingy olive-coloured legs of this species a justification of the English name by which it goes, and the application of that name, which seems to be due to Pennant, was probably by way of distinguishing it from two allied but perfectly distinct species ofTotanus(T. calidrisandT. fuscus) having red legs and usually called redshanks. The greenshank is a native of the northern parts of the Old World, but in winter it wanders far to the south, and occurs regularly at the Cape of Good Hope, in India and thence throughout the Indo-Malay Archipelago to Australia. It has also been recorded from North America, but its appearance there must be considered accidental. Almost as bulky as a woodcock, it is of a much more slender build, and its long legs and neck give it a graceful appearance, which is enhanced by the activity of its actions. Disturbed from the moor or marsh, where it has its nest, it rises swiftly into the air, conspicuous by its white back and rump, and uttering shrill cries flies round the intruder. It will perch on the topmost bough of a tree, if a tree be near, to watch his proceedings, and the cock exhibits all the astounding gesticulations in which the males of so many otherLimicolaeindulge during the breeding-season—with certain variations, however, that are peculiarly its own. It breeds in no small numbers in the Hebrides, and parts of the Scottish Highlands from Argyllshire to Sutherland, as well as in the more elevated or more northern districts of Norway, Sweden and Finland, and probably also thence to Kamchatka. In North America it is represented by two species,Totanus semipalmatusandT. melanoleucus, there called willets, telltales or tattlers, which in general habits resemble the greenshank of the Old World.

(A. N.)

GREENVILLE,a city and the county-seat of Washington county, Mississippi, U.S.A., on the E. bank of the Mississippi river, about 75 m. N. of Vicksburg. Pop. (1890) 6658; (1900) 7642 (4987 negroes); (1910) 9610. Greenville is served by the Southern and the Yazoo & Mississippi Valley railways, and by various passenger and freight steamboat lines on the Mississippi river. It is situated in the centre of the Yazoo Delta, a rich cotton-producing region, and its industries are almost exclusively connected with that staple. There are large warehouses, compresses and gins, extensive cotton-seed oil works and sawmills. Old Greenville, about 1 m. S. of the present site, was the county seat of Jefferson county until 1825 (when Fayette succeeded it), and later became the county-seat of Washington county. Much of the old town caved into the river, and during the Civil War it was burned by the Federal forces soon after the capture of Memphis. The present site was then adopted. The town of Greenville was incorporated in 1870; in 1886 it was chartered as a city.

GREENVILLE,a city and the county-seat of Darke county, Ohio, U.S.A., on Greenville Creek, 36 m. N.W. of Dayton. Pop. (1900) 5501; (1910) 6237. It is served by the Pittsburg, Cincinnati, Chicago & St Louis and the Cincinnati Northern railways, and by interurban electric railways. It is situated about 1050 ft. above sea-level and is the trade centre of a large and fertile agricultural district, producing cereals and tobacco. It manufactures lumber, foundry products, canned goods and creamery products and has grain elevators and tobacco warehouses. In the city is a Carnegie library, and 3 m. distant there is a county Children’s Home and Infirmary. The municipality owns and operates its water-works. Greenville occupies the site of an Indian village and of Fort Greenville (built by General Anthony Wayne in 1793 and burned in 1796). Here, on the 3rd of August 1795, General Wayne, the year after his victory over the Indians at Fallen Timbers, concluded with them the treaty of Greenville, the Indians agreeing to a cessation of hostilities and ceding to the United States a considerable portion of Ohio and a number of small tracts in Indiana, Illinois and Michigan (including the sites of Sandusky, Toledo, Defiance, Fort Wayne, Detroit, Mackinac, Peoria and Chicago), and the United States agreeing to pay to the Indians $20,000 worth of goods immediately and an annuity of goods, valued at $9500, for ever. The tribes concerned were the Wyandots, the Delawares, the Shawnees, the Ottawas, the Chippewas, the Pottawatomies, the Miamis, the Weeas, the Kickapoos, the Piankashas, the Kaskaskias and the Eel-river tribe. Tecumseh lived at Greenville from 1805 to 1809, and a second Indian treaty was negotiated there in July 1814 by General W. H. Harrison and Lewis Cass, by which the Wyandots, the Delawares, the Shawnees, the (Ohio) Senecas and the Miamis agreed to aid the United States in the war with Great Britain. The first permanent white settlement of Greenville was established in 1808 and the town was laid out in the same year. It was made the county-seat of the newly erected county in 1809, was incorporated as a town in 1838 and chartered as a city in 1887.

GREENVILLE,a city and the county-seat of Greenville county, South Carolina, U.S.A., on the Reedy river, about 140 m. N.W. of Columbia, in the N.W. part of the state. Pop. (1890) 8607; (1900) 11,860, of whom 5414 were negroes; (1910, census) 15,741. It is served by the Southern, the Greenville & Knoxville and the Charleston & Western Carolina railways. It lies 976 ft. above sea-level, near the foot of the Blue Ridge Mountains, its climate and scenery attracting summer visitors. It is in an extensive cotton-growing and cotton-manufacturing district. Greenville’s chief interest is in cotton, but it has various other manufactures, including carriages, wagons, iron and fertilizers. The total value of the factory products of the city in 1905 was $1,676,774, an increase of 73.5% since 1900. The city is the seat of Furman University, Chicora College for girls (1893; Presbyterian), and Greenville Female College (1854; Baptist), which in 1907-1908 had 379 students, and which, besides the usual departments, has a conservatory of music, a school of art, a school of expression and physical culture and a kindergarten normal training school. Furman University (Baptist; opened in 1852) grew out of the “Furman Academy and Theological Institution,” opened at Edgefield, S.C., in 1827, and named in honour of Richard Furman (1755-1825), a well-known Baptist clergyman of South Carolina, whose son, James C. Furman (1809-1891), was long president of the University. In 1907-1908 the university had a faculty of 15 and 250 students, of whom 101 were in the Furman Fitting School. Greenville was laid out in 1797, was originally known as Pleasantburg and was first chartered as a city in 1868.

GREENVILLE,a city and the county-seat of Hunt county, Texas, U.S.A., near the headwaters of the Sabine river, 48 m. N.E. of Dallas. Pop. (1900) 6860, of whom 114 were foreign-born and 1751 were negroes; (1910) 8850. It is served by the Missouri, Kansas & Texas, the St Louis South-Western and the Texas Midland railways. It is an important cotton market, has gins and compresses, a large cotton seed oil refinery, and other manufactories, and is a trade centre for a rich agricultural district. The city owns and operates its electric-lighting plant. It is the seat of Burleson College (Baptist), founded in 1893, and 1 m. from the city limits, in the village of Peniel (pop. 1908, about 500), a community of “Holiness” people, are the Texas Holiness University (1898), a Holiness orphan asylum and a Holiness press. Greenville was settled in 1844, and was chartered as a city in 1875. In 1907 the Texas legislature granted to the city a new charter establishing a commission government similar to that of Galveston.

GREENWICH,a township of Fairfield county, Connecticut, U.S.A., on Long Island Sound, in the extreme S.W. part of the state, about 28 m. N.E. of New York City. It contains a borough of the same name and the villages of Cos Cob, Riverside and Sound Beach, all served by the New York, New Haven & Hartford Railway; the township has steamboat and electric railway connexions with New York City. Pop. of the township (1900) 12,172, of whom 3271 were foreign-born; (1910) 16,463; of the borough (1910) 3886. Greenwich is a summer resort, principally for New Yorkers. Among the residents have been Edwin Thomas Booth, John Henry Twachtman, the landscape painter, and Henry Osborne Havemeyer (1847-1907), founder of the American Sugar Company. There are several fine churches in the township; of one in Sound Beach the Rev. William H. H. Murray (1840-1904), called “Adirondack Murray,” from hisCamp Life in the Adirondack Mountains(1868), was once pastor. In the borough are a public library, Greenwich Academy (1827; co-educational), the Brunswick School for boys (1901), with which Betts Academy of Stamford was united in 1908, and a hospital. The principal manufactures are belting, woollens, tinners’ hardware, iron and gasolene motors. Oysters are shipped from Greenwich. The first settlers came from the New Haven Colony in 1640; but the Dutch, on account of the exploration of Long Island Sound by Adrian Blok in 1614, laid claim to Greenwich, and as New Haven did nothing to assist the settlers, they consented to union with New Netherland in 1642. Greenwich then became a Dutch manor. By a treaty of 1650, which fixed the boundary between New Netherland and the New Haven Colony, the Dutch relinquished their claim to Greenwich, but the inhabitants of the town refused to submit to the New Haven Colony until October 1656. Six years later Greenwich was one of the first towns of the New Haven Colony to submit to Connecticut. The township suffered severely during the War of Independence on account of the frequent quartering of American troops within its borders, the depredations of bands of lawless men after the occupation of New York by the British in 1778 and its invasion by the British in 1779 (February 25) and 1781 (December 5). There was also a strong loyalist sentiment. On the old post-road in Greenwich is the inn, built about 1729, at which Israel Putnam was surprised in February 1779 by a force under General Tryon; according to tradition he escaped by riding down a flight of steep stone steps. The inn was purchased in 1901 by the Daughters of the American Revolution, who restored it and made it a Putnam Memorial. The township government of Greenwich was instituted in the colonial period. The borough of Greenwich was incorporated in 1858.

See D. M. Mead,History of the Town of Greenwich(New York, 1857).

GREENWICH,a south-eastern metropolitan borough of London, England, bounded N. by the river Thames, E. by Woolwich, S. by Lewisham and W. by Deptford. Pop. (1901) 95,770. Area, 3851.7 acres. It has a river-frontage of 4½ m., the Thames making two deep bends, enclosing the Isle of Dogs on the north and a similar peninsula on the Greenwich side. Greenwich is connected with Poplar on the north shore by the Greenwich tunnel (1902), for foot-passengers, to the Isle of Dogs (Cubitt Town), and by the Blackwall Tunnel (1897) for street traffic, crossing to a point between the East and West India Docks (seePoplar). The main thoroughfares from W. to E. are Woolwich and Shooter’s Hill Roads, the second representing the old high road through Kent, the Roman Watling Street. Greenwich is first noticed in the reign of Ethelred, when it was a station of the Danish fleet (1011-1014).

The most noteworthy buildings are the hospital and the observatory. Greenwich Hospital, as it is still called, became in 1873 a Royal Naval College. Upon it or its site centre nearly all the historical associations of the place. The noble buildings, contrasting strangely with the wharves adjacent and opposite to it, make a striking picture, standing on the low river-bank with a background formed by the wooded elevation of Greenwich Park. They occupy the site of an ancient royal palace called Greenwich House, which was a favourite royal residence as early as 1300, but was granted by Henry V. to Thomas Beaufort, duke of Exeter, from whom it passed to Humphrey, duke of Gloucester, who largely improved the property and named itPlacentia. It did not revert to the crown till his death in 1447. It was the birthplace of Henry VIII., Queen Mary and Queen Elizabeth, and here Edward VI. died. The building was enlarged by Edward IV., by Henry VIII., who made it one of his chief residences, by James I. and by Charles I., who erected the “Queen’s House” for Henrietta Maria. The tenure of land from the crown “as of the manor of East Greenwich” became at this time a recognized formula, and occurs in a succession of American colonial charters from those of Virginia in 1606, 1609 and 1612 to that of New Jersey in 1674. Along with other royal palaces Greenwich was at the Revolution appropriated by the Protector, but it reverted to the crown on the restoration of Charles II., by whom it was pulled down, and the west wing of the present hospital was erected as part of an extensive design which was not further carried out. In its unfinished state it was assigned by the patent of William and Mary to certain of the great officers of state, as commissioners for its conversion into a hospital for seamen; and it was opened as such in 1705. The building consists of four blocks. Behind a terrace 860 ft. in length, stretching along the river side, are the buildings erected in the time of Charles II. from Inigo Jones’s designs, and in that of Queen Anne from designs by Sir Christopher Wren; and behind these buildings are on the west those of King William and on the east those of Queen Mary, both from Wren’s designs. In the King William range is the painted hall. Here in 1806 the remains of Nelson lay in state before their burial in St Paul’s Cathedral. Its walls and ceiling were painted by Sir James Thornhill with various emblematic devices, and it is hung with portraits of the most distinguished admirals and paintings of the chief naval battles of England. In the Queen Anne range is the Royal Naval Museum, containing models, relics of Nelson and of Franklin, and other objects. In the centre of the principal quadrangle of the hospital there is a statue of George II. by Rysbrack, sculptured out of a single block of marble taken from the French by Admiral Sir George Rooke. In the upper quadrangle is a bust of Nelson by Chantrey, and there are various other memorials and relics. The oldest part of the building was in some measure rebuilt in 1811, and the present chapel was erected to replace one destroyed by fire in 1779. The endowments of the hospital were increased at various periods from bequests and forfeited estates. Formerly 2700 retired seamen were boarded within it, and 5000 or 6000 others, called out-pensioners, received stipends at various rates out of its funds; but in 1865 an act was passed empowering the Admiralty to grant liberal pensions in lieu of food and lodging to such of the inmates as were willing to quit the hospital, and in 1869 another act was passed making their leaving on these conditions compulsory. It was then devoted to the accommodation of the students of the Royal Naval College, the Infirmary being granted to the Seamen’s Hospital Society. Behind the College is the Royal Hospital School, where 1000 boys, sons of petty officers and seamen, are boarded.

To the south of the hospital is Greenwich Park (185 acres), lying high, and commanding extensive views over London, the Thames and the plain of Essex. It was enclosed by Humphrey, duke of Gloucester, and laid out by Charles II., and contains a fine avenue of Spanish chestnuts planted in his time. In it is situated the Royal Observatory, built in 1675 for the advancement of navigation and nautical astronomy. From it the exact time is conveyed each day at one o’clock by electric signal to the chief towns throughout the country; British and the majority of foreign geographers reckon longitude from its meridian. A standard clock and measures are seen at the entrance. A new building was completed in 1899, the magnetic pavilion lying some 400 yds. to the east, so placed to avoid the disturbance of instruments which would be occasioned by the iron used in the principal building. South of the park lies the open common of Blackheath, mainly within the borough of Lewisham, and in the east the borough includes the greater part of Woolwich Common.

At Greenwich an annual banquet of cabinet ministers, known as the whitebait dinner, formerly took place. This ceremony arose out of a dinner held annually at Dagenham, on the Essex shore of the Thames, by the commissioners for engineering works carried out there in 1705-1720—a remarkable achievement for this period—to save the lowlands from flooding. To one of these dinners Pitt was invited, and was subsequently accompanied by some of his colleagues. Early in the 19th century the venue of the dinner, which had now become a ministerial function, was transferred to Greenwich, and though at first not always held here, was later celebrated regularly at the “Ship,” an hotel of ancient foundation, closed in 1908. The banquet continued till 1868, was revived in 1874-1880, and was held for the last time in 1894.

The parish church of Greenwich, in Church Street, is dedicated to St Alphege, archbishop, who was martyred here by the Danes in 1012. In the church Wolfe, who died at Quebec (1759), and Tallis, the musician, are buried. A modern stained-glass window commemorates Wolfe.

The parliamentary borough of Greenwich returns one member. Two burgesses were returned in 1577, but it was not again represented till the same privilege was conferred on it in 1832. The borough council consists of a mayor, five aldermen and thirty councillors.

GREENWOOD, FREDERICK(1830-1909), English journalist and man of letters, was born in April 1830. He was one of three brothers—the others being James and Charles—who all gained reputation as journalists. Frederick started life in a printing house, but at an early age began to write in periodicals. In 1853 he contributed a sketch of Napoleon III. to a volume calledThe Napoleon Dynasty(2nd ed., 1855). He also wrote several novels:The Loves of an Apothecary(1854),The Path of Roses(1859) and (with his brother James)Under a Cloud(1860). To the second number of theCornhill Magazinehe contributed “An Essay without End,” and this led to an introduction to Thackeray. In 1862, when Thackeray resigned the editorship of theCornhill, Greenwood became joint editor with G. H. Lewes. In 1864 he was appointed sole editor, a post which he held until 1868. While at theCornhillhe wrote an article in which he suggested, to some extent, how Thackeray might have intended to conclude his unfinished workDenis Duval, and in its pages appearedMargaret Denzil’s History, Greenwood’s most ambitious work of fiction, published in volume form in 1864. At that time Greenwood had conceived the idea of an evening newspaper, which, while containing “all the news proper to an evening journal,” should, for the most part, be made up “of original articles upon the many things which engage the thoughts, or employ the energies, or amuse the leisure of mankind.” Public affairs, literature and art, “and all the influences which strengthen or dissipate society” were to be discussed by men whose independence and authority were equally unquestionable. Canning’sAnti-Jacobinand theSaturday Reviewof 1864 were the joint models Greenwood had before him. The idea was taken up by Mr George Smith, and thePall Mall Gazette(so named after Thackeray’s imaginary paper inPendennis) was launched in February 1865, with Greenwood as editor. Within a few years he had come to exercise a great influence on public affairs. His views somewhat rapidly ripened from what was described as philosophic Liberalism into Conservatism. No minister in Great Britain, Mr Gladstone declared, ever had a more able, a more zealous, a more effective supporter for his policy than Lord Beaconsfieldhad in Greenwood. It was on the suggestion of Greenwood that Beaconsfield purchased in 1875 the Suez Canal shares of the Khedive Ismail; the British government being ignorant, until informed by Greenwood, that the shares were for sale and likely to be bought by France. It was characteristic of Greenwood that he declined to publish the news of the purchase of the shares in thePall Mallbefore the official announcement was made.

Early in 1880 thePall Mallchanged owners, and the new proprietor required it to support Liberal policy. Greenwood at once resigned his editorship, but in May a new paper, theSt James’s Gazette, was started for him by Mr Henry Hucks Gibbs (afterwards Lord Aldenham), and Greenwood proceeded to carry on in it the tradition which he had established in thePall Mall. At theSt James’sGreenwood remained for over eight years, continuing to exercise a marked influence upon political affairs, notably as a pungent critic of the Gladstone administration (1880-1885) and an independent supporter of Lord Salisbury. His connexion with the paper ceased in August 1888, owing to disagreements with the new proprietor, Mr E. Steinkopff, who had bought theSt James’sat Greenwood’s own suggestion. In January 1891 Greenwood brought out a weekly review which he named theAnti-Jacobin. It failed, however, to gain public support, the last number appearing in January 1892. In 1893 he publishedThe Lover’s Lexiconand in 1894Imagination in Dreams. He continued to express his views on political and social questions in contributions to newspapers and magazines, writing frequently in theWestminster Gazette, thePall Mall,Blackwood, theCornhill, &c. Towards the end of his life his political views reverted in some respects to the Liberalism of his early days.

In the words of George Meredith “Greenwood was not only a great journalist, he had a statesman’s head. The national interests were always urgent at his heart.” He was remarkable for securing for his papers the services of the ablest writers of the day, and for the gift of recognizing merit in new writers, such, for instance, as Richard Jeffries and J. M. Barrie. His instinct for capacity in others was as sure as was his journalistic judgment. In 1905, on the occasion of his 75th birthday, a dinner was given in his honour by leading statesmen, journalists, and men of letters (with John Morley—who had succeeded him as editor of thePall Mall—in the chair). In May 1907 he contributed toBlackwoodan article on “The New Journalism,” in which he drew a sharp contrast between the old and the new conditions under which the work of a newspaper writer is conducted. He died at Sydenham on the 14th of December 1909.

SeeHonouring Frederick Greenwood, being a report of the speeches at the dinner on the 8th of April 1905 (London, privately printed, 1905); “Birth and Infancy of thePall Mall Gazette,” an article contributed by Greenwood to thePall Mallof the 14th of April 1897; “The Blowing of the Trumpet” in the introduction to theSt James’s(May 31, 1880); obituary notices in theAthenaeum(Dec. 25, 1909) andThe Times(Dec. 17, 1909).

GREENWOOD, JOHN(d. 1593), English Puritan and Separatist (the date and place of his birth are unknown), entered as a sizar at Corpus Christi College, Cambridge, on the 18th of March 1577-1578, and commenced B.A. 1581. Whether he was directly influenced by the teaching of Robert Browne (q.v.), a graduate of the same college, is uncertain; in any case he held strong Puritan opinions, which ultimately led him to Separatism of the most rigid type. In 1581 he was chaplain to Lord Rich, at Rochford, Essex. At some unspecified time he had been made deacon by John Aylmer, bishop of London, and priest by Thomas Cooper, bishop of Lincoln; but ere long he renounced this ordination as “wholly unlawful.” Details of the next few years are lacking; but by 1586 he was the recognized leader of the London Separatists, of whom a considerable number had been imprisoned at various times since 1567. Greenwood was arrested early in October 1586, and the following May was committed to the Fleet prison for an indefinite time, in default of bail for conformity. During his imprisonment he wrote some controversial tracts in conjunction with his fellow-prisoner Henry Barrowe (q.v.). He is understood to have been at liberty in the autumn of 1588; but this may have been merely “the liberty of the prison.” However, he was certainly at large in September 1592, when he was elected “teacher” of the Separatist church. Meanwhile he had written (1590) “An Answer to George Gifford’s pretended Defence of Read Prayers.” On the 5th of December he was again arrested; and the following March was tried, together with Barrowe, and condemned to death on a charge of “devising and circulating seditious books.” After two respites, one at the foot of the gallows, he was hanged on the 6th of April 1593.

Authorities.—H. M. Dexter,Congregationalism during the last three hundred years;The England and Holland of the Pilgrims; F. J. Powicke,Henry Barrowe and the Exiled Church of Amsterdam; B. Brook,Lives of the Puritans; C. H. Cooper,Athenae Cantabrigienses, vol. ii.

GREG, WILLIAM RATHBONE(1809-1881), English essayist, the son of a merchant, was born at Manchester in 1809. He was educated at the university of Edinburgh and for a time managed a mill of his father’s at Bury, and in 1832 began business on his own account. He entered with ardour into the struggle for free trade, and obtained in 1842 the prize offered by the Anti-Corn Law League for the best essay on “Agriculture and the Corn Laws.” He was too much occupied with political, economical and theological speculations to give undivided attention to his business, which he gave up in 1850 to devote himself to writing. HisCreed of Christendomwas published in 1851, and in 1852 he contributed no less than twelve articles to four leading quarterlies. Disraeli praised him; Sir George Cornewall Lewis bestowed a Commissionership of Customs upon him in 1856; and in 1864 he was made Comptroller of the Stationery Office. Besides contributions to periodicals he produced several volumes of essays on political and social philosophy. The general spirit of these is indicated by the titles of two of the best known,The Enigmas of Life(1872) andRocks Ahead(1874). They represent a reaction from the high hopes of the author’s youth, when wise legislation was assumed to be a remedy for every public ill. Greg was a man of deep moral earnestness of character and was interested in many philanthropic works. He died at Wimbledon on the 15th of November 1881. His brother,Robert Hyde Greg(1795-1875), was an economist and antiquary of some distinction. Another brother,Samuel Greg(1804-1876), became well known in Lancashire by his philanthropic efforts on behalf of the working-people.Percy Greg(1836-1889), son of William Rathbone Greg, also wrote, like his father, on politics, but his views were violently reactionary. HisHistory of the United States to the Reconstruction of the Union(1887) is a polemic rather than a history.

GREGARINES(mod. Lat.Gregarina, fromgregarius, collecting in a flock or herd,grex) a large and abundant order of Sporozoa Ectospora, in which a very high degree of morphological specialization and cytological differentiation of the cell-body is frequently found. On the other hand, the life-cycle is, in general, fairly simple. Other principal characters which distinguish Gregarines from allied Sporozoan parasites are as follows:—The fully-grown adult (trophozoite) is always “free” in some internal cavity,i.e.it is extracellular; in nearly all cases prior to sporulation two Gregarines (associates) become attached to one another, forming a couple (syzygy), and are surrounded by a common cyst; inside the cyst the body of each associate becomes segmented up into a number of sexual elements (gametes, primary sporoblasts), which then conjugate in pairs; the resulting copula (zygote, definitive sporoblast) becomes usually a spore by the secretion of spore-membranes (sporocyst), its protoplasm (sporoplasm) dividing up to form the germs (sporozoites).

F. Redi (1684) is said to have been the first to observe a Gregarine parasite, but his claim to this honour is by no means certain. Much later (1787) Cavolini described and figured an indubitable Gregarine (probably theHistorical.form now known asAggregata conformis) from a Crustacean (Pachygrapsus), which, however, he regarded as a tapeworm. Leon Dufour, who in his researches on insect anatomy came across several species of these parasites, also considered them as allied to the worms and proposed the generic name ofGregarina.The unicellular nature of Gregarines was first realized by A. von Kölliker, who from 1845-1848 added considerably to our knowledge of the frequent occurrence and wide distribution of these organisms. Further progress was due to F. Stein who demonstrated about this time the relation of the “pseudo-navicellae” (spores) to the reproduction of the parasites.

Apart from the continually increasing number of known species, matters remained at about this stage for many years. It is, in fact, only since the closing years of the 19th century that the complete life-history has been fully worked out; this has now been done in many cases, thanks to the researches of M. Siedlecki, L. Cuénot, L. Léger, O. Duboscq, A. Laveran, M. Caullery, F. Mesnil and others, to whom also we owe most of our knowledge regarding the relations of the parasites to the cells of their host during their early development.

Gregarines are essentially parasites of Invertebrates; they are not known to occur in any true Vertebrate although met with in Ascidians. By far the greatest number of hosts is furnished by the Arthropods. Many members of theOccurrence; mode of infection.various groups of worms (especially the Annelids) also harbour the parasites, and certain very interesting forms are found in Echinoderms; in the other classes, they either occur only sporadically or else are absent. Infection is invariably of the accidental (casual) type, by way of the alimentary canal, the spores being usually swallowed by the host when feeding; a novel variation of this method has been described by Woodcock (31) in the case of a Gregarine parasitic in Cucumaria, where the spores are sucked up through the cloaca into the respiratory trees, by the inhalant current.

The favourite habitat is either the intestine (fig. 1) or its diverticula (e.g.the Malpighian tubules), or the body-cavity. In the latter case, after infection has occurred, the liberated germs at once traverse the intestinal epithelium. They mayHabitat and effects on host.come to rest in the connective tissue of the sub-mucosa (remaining, however, extracellular), grow considerably in that situation, and ultimately fall into the body-cavity (e.g.Diplocystis); or they may pass straightway into the body-cavity and there come into relation with some organ or tissue (e.g.Monocystis) of the earthworm, which is for a time intracellular in the spermatoblasts (fig. 4,c). In the case of intestinal Gregarines, the behaviour of the young trophozoite with respect to the epithelial cells of its host varies greatly. The parasite may remain only attached to the host-cell, never becoming actually intracellular (e.g.Pterocephalus); more usually it penetrates partially into it, the extracellular portion of the Gregarine, however, giving rise subsequently to most of the adult (e.g.Gregarina); or lastly, in a few forms, the early development is entirely intracellular (e.g.Lankesteria,Stenophora).

Fig.3.—Porospora gigantea f, (E. van Ben.), from the intestine of the lobster.a, Nucleus.

Fig.4.

a-c, Trophozoites ofMonocystis agilis.

aandb, Young individuals showing changes of body-form.

c, Older individual, still enveloped in a coat of spermatozoa.

d,e, Trophozoites ofM. magnaattached to seminal funnel ofLumbricus.

Goblet-shaped epithelial cells, in which the extremity of the parasite is inserted.

The effects on the host are confined to the parasitized cells. These generally undergo at first marked hypertrophy and alteration in character; this condition is succeeded by one of atrophy, when the substance of the cell becomes in one way or another practically absorbed by the growing parasite (cf. alsoCoccidia). Since, however, the Gregarines never overrun their hosts in the way that many other Sporozoa do (because of their lack, in general, of the power of endogenous multiplication), the number of cells of any tissue attacked, even in the case of a strong infection, is only a very small percentage of the whole. In short the hosts do not, as a rule, suffer any appreciable inconvenience from the presence of the parasites.

The body of a Gregarine is always of a definite shape, usually ovalor elongated; in one or two instances (e.g.Diplodina) it is spherical, and, on the other hand, inPorospora(fig. 3) it is greatly drawn out and vermiform. In many adult Gregarines,Morphology.the body is divided into two distinct but unequal regions or halves, the anterior part being known as theprotomerite, the hinder, generally the larger, as thedeutomerite. This feature is closely associated with another important morphological character, one which is observable, however, only during the earlier stages of growth and development, namely, the presence of a definite organ, theepimerite, which serves for the attachment of the parasite to the host-cell (fig. 6).In those Gregarines (most intestinal forms) which become attached to an epithelial cell, the attachment occurs by means of a minute projection or beak (rostrum) at the anterior end of the sporozoite, which pushes its way into the cell, followed by the first part of the growing germ. This portion of the body increases in size much quicker at first than the rest (the extracellular part), more or less fills up the host-cell, and forms the well-developed epimerite or secondary attaching organella. The extracellular part of the Gregarine next grows rapidly, and a transverse septum is formed at a short distance away from (outside) the point where the body penetrates into the cell (fig. 6); this marks off the large deutomerite posteriorly (distally). Léger thinks that this partition most likely owes its origin to trophic considerations,i.e.to the slightly different manner in which the two halves of the young parasite (the proximal, largely intracellular part, and the distal, extracellular one) may be supposed to obtain their nutriment. In the case of the one half, the host-cell supplies the nutriment, in that of the other, the intestinal liquid; and the septum is, as it were, the expression of the conflicting limit between these two methods. Nevertheless, the present writer does not think that mechanical considerations should be altogether left out of account. The septum may also be, to some extent, an adaption for strengthening the body of the fixed parasite against lateral thrusts or strains, due to the impact of foreign bodies (food, &c.) in the intestine.At the point where the body becomes actually intracellular, it is constricted, and this constriction marks off the epimerite (internally) from the middle portion (between this point and the septum), which is the protomerite. Further growth is restricted, practically, to the extracellular regions, and the epimerite often comes to appear ultimately as a small appendage at the anterior end of the protomerite. A Gregarine at this stage is known as a cephalont. Later on, the parasite breaks loose from the host-cell and becomes free in the lumen, the separation taking place at the constriction between the protomerite and the epimerite; the latter is left behind in the remains of the host-cell, the former becomes the anterior part of the free trophozoite.In other Gregarines, however, those, namely, which pass inwards, ultimately becoming “coelomic,” as well as those which become entirely intracellular, no epimerite is ever developed, and, further, the body remains single or unseptate. These forms, which include, for instance,Monocystis(fig. 4),Lankesteria,Diplocystis, are distinguished, asAcephalinaorAseptata(Haplocyta,Monocystida), according to which character is referred to, from the others, termedCephalinaorSeptata(Polycystida).The two sets of terms are not, however, completely identical or interchangeable, for there are a few forms which possess an epimerite, but which lack the division into protomerite and deutomerite, and are hence known asPseudomonocystida; this condition may be primitive (Doliocystis) or (possibly) secondary, the partition having in course of time disappeared. Again,Stenophorais a septate form which has become, secondarily, completely intracellular during the young stages, and, doubtless correlated with this, shows no sign of an epimerite.From Wasielewski, after Léger.Fig. 7.—Forms of Epimerites.1,Gregarina longa.2,Sycia inopinata.3,Pileocephalus heerii.4,Stylorhynchus longicollis.5,Beloides firmus.6,Cometoides crinitus.7,Geneiorhynchus monnieri.8,Echinomera hispida.9,Pterocephalus nobilis.With regard to the epimerites themselves, they are of all variety of form and shape and need not be described in detail (fig. 7). In one or two cases, however, another variety of attaching organella is met with. Thus inPterocephalus, only the rostrum of the sporozoite penetrates into the host-cell, and no epimerite is formed. Instead, a number of fine root-like processes are developed from near the anterior end, which pass in between the host-cells (fig. 5) and thus anchor the parasite firmly. Similarly, in the curiousSchizogregarinae, the anterior end of the (unseptate) body forms a number of stiff, irregular processes, which perform the same function (fig. 8). It is to be noted that these processes are non-motile, and not in any way comparable to pseudopodia, to which they were formerly likened.A very interesting and remarkable morphological peculiarity has been recently described by Léger (18) in the case of a new Gregarine,Taeniocystis. In this form the body is elongated and metamerically segmented, recalling that of a segmented worm, the adult trophozoites possessing numerous partitions or segments (each corresponding to the septum between the proto- and deuto-merite in an ordinary Polycystid), which divide up the cytoplasm into roughly equal compartments. Léger thinks only the deutomerite becomes thus segmented, the protomerite remaining small and undivided. The nucleus remains single, so that there is no question as to the unicellular or individual nature of the entire animal.After Léger and Hagenmüller, from Lankester’sTreatise on Zoology.Fig. 8.—Three Individuals (G) ofOphryocystis schneideri, attached to wall of Malpighian tubule ofBlapssp.p, Syncytial protoplasm of the tubule;c, Cilia lining the lumen.The general cytoplasm usually consists of distinct ectoplasm and endoplasm, and is limited by a membrane or cuticle (epicyte), secreted by the former. The cuticle varies considerably in thickness, being well developed in active, intestinalMinute structure.forms, but very thin and delicate in non-motile coelomic forms (e.g.Diplodina). In the former case it may show longitudinal striations. The cuticle also forms the hooks or spines of many epimerites. The ectoplasm usually shows (fig. 9A) a differentiation into two layers, an outer, firmer layer, clear and hyaline, the sarcocyte, and an inner layer, the myocyte, which is formed of a network of muscle-fibrillae (mainly longitudinal and transverse, fig. 9B). The sarcocyte alone constitutes the septum, traversing the endoplasm, in septate Gregarines. The myonemes are undoubtedly the agents responsible for the active “gregarinoid” movements (of flexion and contraction) to be observed in many forms. The peculiar gliding movements were formerly thought to be produced by the extrusion of a gelatinous thread posteriorly, but Crawley (8) has recently ascribed them to a complicated succession of wave-like contractions of the myocyte layer. This view is supported by the fact that certain coelomic forms, likeDiplodinaand others, which either lack muscle-fibrils or else show no ectoplasmic differentiation at all, are non-motile. The endoplasm, or nutritive plasm, consists of a semi-fluid matrix in which are embedded vast numbers of grains and spherules of various kinds and of all sizes, representing an accumulation of food-material which is being stored up prior to reproduction. The largest and most abundant grains are of a substance termed para-glycogen, a carbohydrate; in addition, flattenedlenticular platelets, of an albuminoid character, and highly-refringent granules often occur.After Schewiakoff, from Lankester’sTreatise on Zoology.Fig. 9a.—Longitudinal section of a Gregarine in the region of the septum between protomerite and deutomerite.Pr, Protomerite.De, Deutomerite.s, Septum.en, Endoplasm.sc, Sarcocyte.c, Cuticle.m,f, Myocyte fibrils (cut across).g, Gelatinous layer.Fig. 9b.—Gregarina munieri, showing the network of myocyte fibrillae.The nucleus is always lodged in the endoplasm, and, in the septate forms, in the deutomeritic half of the body. It is normally spherical and always limited by a distinct nuclear membrane, which itself often contains chromatin. The most characteristic feature of the nucleus is the deeply-staining, more or less vacuolated spherical karyosome (consisting of chromatin intimately bound up with a plastinoid basis) which is invariably present. In one or two instances (e.g.Diplocystis schneideri) the nucleus has more than one karyosome. All the chromatin of the nucleus is not, however, confined to the karyosome, some being in the form of grains in the nuclear sap; and in some cases at any rate (e.g.Diplodina, Lankesteria) there is a well-marked nuclear reticulum which is impregnated with granules and dots of chromatin.From Wasielewski, after A. Schneider.Fig. 10.—Schizogony inOphryocystis francisci.a, Rosette of small individuals, produced from a schizont which has just divided;b, A later stage, the daughter-individuals about to separate and assuming the characters of the adult.From Wasielewski, after Léger.Fig. 11.—Eirmocystis spp. a,b, Associations of two and three Gregarines;c, Chain of five parasites;p, Primite;s, Satellites.A sexual multiplication (schizogony) is only known certainly to occur in a few cases, one being in a Monocystid form, a species ofGonospora, which is for a long time intracellular (Caullery and Mesnil [4]), the rest among theSchizogregarinae, soLife-history.named for this reason, in which schizogonous fission takes place regularly during the free, trophic condition. Usually, the body divides up, by a process of multiple fission (fig. 10), into a few (up to eight) daughter-individuals; but in a new genus (Eleutheroschizon), Brasil (3) finds that a great number of little merozoites are formed, and a large amount of vacuolated cytoplasm is left over unused.In the vast majority of Gregarines, however, the life-cycle is limited to gametogony and sporogony. A very general, if not indeed universal, prelude to gametogony is the characteristic and important feature of the order, known as association, the biological significance of which has only lately been fully brought out (see H. M. Woodcock [31]). In normal association, two individuals which are to be regarded as of opposite sex, come into close contact with each other and remain thus attached. The manner in which the parasites join varies in different forms; the association may be end-to-end (terminal), either by like or by unlike poles, or it may be side-to-side (lateral) (fig. 12). The couple (syzygy) thus formed may proceed forthwith to encystment and sporoblast-formation (Lankesteria, Monocystis), or may continue in the trophic phase for some time longer (Gregarina). In one or two instances (Zygocystis), association occurs as soon as the trophozoites become adult. This leads on to the interesting phenomenon of precocious association (neogamy), found in non-motile, coelomic Gregarines (e.g.Cystobia,DiplodinaandDiplocystis), in which the parasitism is most advanced. Woodcock (loc. cit.) has described and compared the different methods adopted to ensure a permanent union, and the degree of neogamy attained, in these forms. Here it must suffice to say that, in the extreme condition (seen, for instance, inDiplodina minchinii) the union takes place very early in the life-history, between individuals which are little more than sporozoites, and is of a most intimate character, the actual cytoplasm of the two associates joining. In such cases, there is absolutely nothing to indicate the “double” nature of the growing trophozoite, but the presence of the two nuclei which remain quite distinct.There can be little doubt that, in the great majority, if not in all Gregarines, association is necessary for subsequent sporulation to take place;i.e.that the cytotactic attraction imparts a developmental stimulus to both partners, which is requisite for the formation of primary sporoblasts (gametes). This association is usually permanent; but in one or two cases (perhapsGonospora sp.) temporary association may suffice. While association has fundamentally a reproductive (sexual) significance, in some cases, this function may be delayed or, as it were, temporarily suspended, the cytotactic attraction serving meanwhile a subsidiary purpose in trophic life. Thus, probably, are to be explained the curious multiple associations and long chains of Gregarines (fig. 11) sometimes met with (e.g.Eirmocystis,Clepsydrina).Encystment is nearly always double,i.e.of an associated couple. Solitary encystment has been described, but whether successful independent sporulation results, is uncertain; if it does, the encystment in such cases is, in all probability, only after prior (temporary) association. In the case of free parasites, a well-developed cyst is secreted by the syzygy, which rotates and gradually becomes spherical. A thick, at first gelatinous, outer cyst-membrane (ectocyst) is laid down, and then a thin, but firm internal one (endocyst). The cyst once formed, further development is quite independent of the host, and, in fact, often proceeds outside it. In certain coelomic Gregarines, on the other hand, which remain in very close relation with the host’s tissues, little or nothing of an encystment-process on the part of the parasites is recognizable, the cyst-wall being formed by an enclosing layer of the host (Diplodina).From Wasielewski, after Léger.Fig. 12.—Associations ofGonospora sparsa.The nuclear changes and multiplication which precede sporoblast-formation vary greatly in different Gregarines and can only be outlined here. In the formation of both sets of sexual elements (gametes) there is always a comprehensive nuclear purification or maturation. This elimination of a part of the nuclear material (to be distinguished as trophic or somatic, from the functional or germinal portion, which forms the sexual nuclei) may occur at widely-different periods. In some cases (Lankesteria,Monocystis), a large part of the original (sporont-) nucleus of each associate is at once got rid of, and the resulting (segmentation-) nucleus, which is highly-specialized, represents the sexual part. In other cases, again, the entire sporont-nucleus proceeds to division, and the distinction between somatic and germinal portions does not become manifest until after nuclear multiplication has continued for some little time, when certain of the daughter-nuclei become altered in character, and ultimately degenerate, the remainder giving rise to the sporoblast-nuclei (Diplodina,Stylorhynchus). Even after the actual sporoblasts (sex-cells) themselves are constituted, their nuclei may yet undergo a final maturation (e.g.Clepsydrina ovata); and inMonocystis, indeed, Brasil (2) finds that what is apparently a similar process is delayed until after conjugation and formation of the zygote (definitive sporoblast).Nuclear multiplication is usually indirect, the mitosis being, as arule, more elaborate in the earlier than in the later divisions. The attraction-spheres are generally large and conspicuous, sometimes consisting of a well-developed centrosphere, with or without centrosomic granules, at other times of very large centrosomes with a few astral rays. In those cases where the karyosome is retained, and the sporont-nucleus divides up as a whole, however, the earliest nuclear divisions are direct; the daughter-nuclei being formed either by a process of simple constriction (e.g.Diplodina), or by a kind of multiple fission or fragmentation (GregarinaandSelenidium spp.). Nevertheless, the later divisions, at any rate inDiplodina, are indirect.By the time nuclear multiplication is well advanced or completed, the bodies of the two parent-Gregarines (associates) have usually become very irregular in shape, and produced into numerous lobes and processes. While in some forms (e.g.Monocystis,Urospora,Stylorhynchus) the two individuals remain fairly separate and independent of each other, in others (Lankesteria) they become intertwined and interlocked, often to a remarkable extent (Diplodina). The sexual nuclei next pass to the surface of the processes and segments, where they take up a position of uniform distribution. Around each, a small area of cytoplasm becomes segregated, the whole often projecting as a little bud or hillock from the general surface. These uninuclear protuberances are at length cut off as the sporoblasts or gametes. Frequently a large amount of the general protoplasm of each parent-individual is left over unused, constituting two cystal residua, which may subsequently fuse; inDiplodina, however, practically the whole cytoplasm is used up in the formation of the gametes.After Léger, from Lankester’sTreatise on Zoology.Fig. 13.—Development of the Gametes and Conjugation inStylorhynchus longicollis.a, Undifferentiated gamete, attached to body of parent-individual.b-d, Stages in development of motile male gamete.e, Mature female gamete.f,g, Stages in conjugation and nuclear union of the two elements.h, Zygote (copula).i, Spore, still with single nucleus and undivided sporoplasm.The sporoblasts themselves show all gradations from a condition of marked differentiation into male and female (anisogamy), to one of complete equality (isogamy). Anisogamy is most highly developed inPterocephalus. Here, the male elements (microgametes) are minute, elongated and spindle-like in shape, with a minute rostrum anteriorly and a long flagellum posteriorly, and very active; the female elements (megagametes) are much larger, oblong to ovoid, and quite passive. InStylorhynchusthe difference between the conjugating gametes is not quite so pronounced (fig. 13), the male elements being of about the same bulk as the females, but pyriform instead of round, and possessing a distinct flagellum; a most interesting point about this parasite is that certain highly motile and spermatozoon-like male gametes are formed (fig. 13), which are, however, quite sterile and have acquired a subsidiary function. In other cases, again, the two kinds of element exhibit either very slight differences (Monocystis) or none (Urospora,Gonospora), in size and appearance, the chief distinction being in the nuclei, those of the male elements being smaller and chromatically denser than those of the females.Lastly, inLankesteria,Gregarina,Clepsydrina,DiplocystisandDiplodinacomplete isogamy is found, there being no apparent difference whatever between the conjugating elements. Nevertheless, these forms are also to be regarded as instances of binary sexuality and not merely of exogamy; for it is practically certain that this condition of isogamy is derived from one of typical anisogamy, through a stage such as is seen inGonospora, &c. And, similarly, just as in all instances where the formation of differentiated gametes has been observed, the origin of the two conjugates is from different associates (parent-sporonts), and all the elements arising from the same parent are of the same sex, so it is doubtless the case here.Fig. 14.—Cyst ofMonocystis agilis, the common Gregarine of the Earthworm, showing ripe spores and absence of any residual protoplasm in the cyst. (From Lankester.)The actual union is brought about or facilitated by the well-known phenomenon termed thedanse des sporoblastes, which is due to various causes. In the case of highly-differentiated gametes (Pterocephalus), the actively motile microgametes rush about here and there, and seek out the female elements. InStylorhynchus, Léger has shown that the function of the sterile male gametes is to bring about, by their vigorous movements, themêlée sexuelle. In the forms where the gametes are isogamous or only slightly differentiated and (probably) not of themselves motile, other factors aid in producing the necessary commingling. Thus inGregarina sp.from the mealworm, the unused somata or cystal residua become amoeboid and send out processes which drive the peripherally-situated gametes round in the cyst; in some cases where the residual soma becomes liquefied (Urospora) the movements of the host are considered to be sufficient; and lastly, inDiplodina, owing to the extent to which the intertwining process is carried, if each gamete is not actually contiguous to a suitable fellow-conjugant, a very slight movement or mutual attraction will bring two such, when liberated, into contact.An unusual modification of the process of sporoblast-formation and conjugation, which occurs inOphryocystis, must be mentioned. Here encystment of two associates takes place as usual; the sporont-nucleus of each, however, only divides twice, and one of the daughter-nuclei resulting from each division degenerates. Hence only one sporoblast-nucleus, representing a quarter of the original nuclear-material, persists in each half. Around this some of the cytoplasm condenses, the rest forming a residuum. The sporoblast or gamete thus formed is completely isogamous and normally conjugates with the like one from the other associate, when a single zygote results which becomes a spore containing eight sporozoites, in the ordinary manner. Sometimes, however, the septum between the two halves of the cyst does not break down, in which case parthenogenesis occurs, each sporoblast developing by itself into a small spore.The two conjugating elements unite completely, cytoplasm with cytoplasm and nucleus with nucleus, to form the definitive sporoblast or zygote. The protoplasm assumes a definite outline, generally that of an ovoid or barrel, and secretes a delicate membrane, the ectospore. This subsequently becomes thickened, and often produced into rims, spines or processes, giving rise to the characteristic appearance of the Gregarine spore. Internal to the ectocyst, another, thinner membrane, the endocyst, is also laid down. These two membranes form the spore-wall (sporocyst). Meanwhile the contents of the spore have been undergoing division. By successive divisions, usually mitotic, the zygote-nucleus gives rise to eight daughter-nuclei, each of which becomes the nucleus of a sporozoite. Next, the sporoplasm becomes split longitudinally, around each nucleus, and thus eight sickle-shaped (falciform) sporozoites are formed. There is usually acertain amount of unused sporoplasm left over in the centre of the spore, constituting the sporal residuum. It is important to note that in all known Gregarines, with one exception, the number of sporozoites in the spore is eight; the exception isSelenidium, in many ways far from typical, where the number is half, viz. four.Fig. 15.—Ripe Cyst ofGregarina blattarum, partially emptied. (From Lankester.)a, Channels leading to the sporoducts;b, Mass of spores still left in the cyst;c, Endocyst;d, The everted sporoducts;e, Gelatinous ectocyst.Hitherto a variation from the general mode of spore-formation has been considered to occur in certain Crustacean Gregarines, theAggregatidaeand thePorosporidae. The spores of these forms have been regarded as gymnospores (naked), lacking the enveloping membranes (sporocyst) of the ordinary spores, and the sporozoites, consequently, as developed freely in the cyst. In the case of the first-named parasites, however, what was taken for sporogony has been proved to be really schizogony, and on other grounds these forms are, in the present writer’s opinion, preferably associated with the Coccidia (q.v.). With regard to thePorosporidae, also, it is quite likely that the gymnosporous cysts considered to belong to the GregarinePorospora(as known in the trophic condition) have really no connexion with it, but represent the schizogonous generation of some other form, similar toAggregata; in which case the true spores ofPorosporahave yet to be identified.In the intestine of a fresh host the cysts rupture and the spores are liberated. This is usually largely brought about by the swelling of the residual protoplasm. Sometimes (e.g.Gregarina) long tubular outgrowths, known as sporoducts (fig. 15), are developed from the residual protoplasm, for the passage of the spores to the exterior.The Gregarines are extremely numerous, and include severalClassification.families, characterized, for the most part, by the form of the spores (fig. 16). The specializedSchizogregarinaeare usually separated off from the rest as a distinct sub-order.Sub-order I.—Schizogregarinae.Forms in which schizogonic reproduction is of general occurrence during the extra-cellular, trophic phase. Three genera,Ophryocystis,SchizocystisandEleutheroschizon, different peculiarities of which have been referred to above. Mostly parasitic in the intestine or Malpighian tubules of insects. (In this type of parasite, as exemplified byOphryocystis, the body was formerly wrongly considered as amoeboid, and hence this genus was placed in a special order, theAmoebosporidia.)From Wasielewski, after Léger.Fig. 16.—Spores of various Gregarines.a,Eirmocystis, Sphaerocystis, &c.b,Echinomera, Pterocephalus, &c.c,Gregarina, &c.d,Beloides.e,Ancyrophora.f,Stylorhynchidae(type of).g,Menosporidae.h,Gonospora terebellae.i,Ceratospora.k,Urospora synaptae.Sub-order II.—Eugregarinae.Schizogony very exceptional, only occurring during the intracellular phase, if at all. Gregarines fall naturally into two tribes, described as cephalont and septate, or as acephalont and aseptate (haplocytic), respectively. In strictness, however, as already mentioned, these two sets of terms do not agree absolutely, and whichever set is adopted, the other must be taken into account in estimating the proper position of certain parasites. Here the cephalont or acephalont condition is regarded as the more primary and fundamental.Tribe A.—Cephalina(practically equivalent toSeptata).Save exceptionally, the body possesses an epimerite, at any rate during the early stages of growth, and is typically septate. Mostly intestinal parasites of Arthropods.The chief families, with representative genera, are as follows:Porosporidae, withPorospora gigantea, at present thought to be gymnosporous;Gregarinidae(Clepsydrinidae), withGregarina,Clepsydrina,Eirmocystis,Hyalospora,Cmenidospora,Stenophora;Didymophyidae, withDidymophyes;Dactylophoridae, withDactylophorus,Pterocephalus,Echinomera,Rhopalonia;ActinocephalidaewithActinocephalus,Pyxinia,Coleorhynchus,Stephanophora,Legeria,Stictospora,Pileocephalus,Sciadophora;AcanthosporidaewithAcanthospora,Corycella,Cometoides;MenosporidaewithMenospora,Hoplorhynchus;Stylorhynchidae, withStylorhynchus,Lophocephalus;DoliocystidaewithDoliocystis; andTaeniocystidae, withTaeniocystis. The curious genusSelenidiumis somewhat apart.Tribe B.—Acephalina(practically equivalent toAseptata,Haplocyta).The body never possesses an epimerite and is non-septate. Chiefly coelomic parasites of “worms,” Holothurians and insects.TheAseptatahave not been so completely arranged in families as theSeptata. Léger has distinguished two well-marked ones, but the remaining genera still want classifying more in detail. Fam.Gonosporidae, withGonospora,Diplodina; andUrosporidae, withUrosopora,Cystobia,Lithocystis,Ceratospora; the generaMonocystis,Diplocystis LankesteriaandZygocystisprobably constitute another;Pterosporaand, again,Syncystisare distinct; lastly, certain forms,e.g.Zygosoma,Anchora(Anchorina), are incompletely known.There remains for mention the remarkable parasite, recently described by J. Nusbaum (24) under the appropriate name ofSchaudinnella henleae, which inhabits the intestine ofHenlea leptodera. Briefly enumerated, the principal features in the life-cycle are as follows. The young trophozoites (aseptate) are attached to the intestinal cells, but practically entirely extracellular. Association is very primitive in character and indiscriminate; it takes place indifferently between individuals which will give rise to gametes of the same or opposite sex. Often it is only temporary; at other times it is multiple, several adults becoming more or less enclosed in a gelatinous investment. Nevertheless, in no case does true encystment occur, the sex-cells being developed practically free. The female gametes are large and egg-like; the males, minute and sickle-like, but with no flagellum and apparently non-motile. While many of the zygotes (“amphionts”) resulting from copulation pass out to the exterior, to infect a new host, others, possessing a more delicate investing-membrane, penetrate in between the intestinal cells, producing a further infection (auto-infection). Numerous sporozoites are formed in each zygote. It will be seen thatSchaudinnellais a practically unique form. While, on the one hand, it recalls the Gregarines in many ways, on the other hand it differs widely from them in several characteristic features, being primitive in some respects, but highly specialized in others, so that it cannot be properly included in the order.Schaudinnellarather represents a primitive Ectosporan parasite, which has proceeded upon a line of its own, intermediate between the Gregarines and Coccidia.Bibliography.—Among the important papers relating to Gregarines are the following:1.A. Berndt, “Beitrag zur Kenntnis der ... Gregarinen,”Arch. Protistenk.I, p. 375, 3 pls. (1902);2.L. Brasil, “Recherches sur la reproduction des Grégarines monocystidées,”Arch. zool. exp.(4) 3, p. 17, pl. 2 (1905), andop. cit.4, p. 69, 2 pls. (1905);3.L. Brazil, “Eleutheroschizon duboscqi, parasite nouveau, &c.,”op. cit.(N. et R.) (4), p. xvii., 5 figs. (1906);4.M. Caullery and F. Mesnil, “Sur une Grégarine ... présentant ... une phase de multiplication asporulée,”C.R. Ac. Sci.126, p. 262 (1898);5.M. Caullery and F. Mesnil, “Le Parasitisme intracellulaire des Grégarines,”op. cit.132, p. 220 (1901);6.M. Caullery and F. Mesnil, “Sur une mode particulière de division nucléaire chez les Grégarines,”Arch. anat. microsc.3, p. 146, 1 pl. (1900);7.M. Caullery and F. Mesnil, “Sur quelques parasites internes des Annélides,”Misc. biol.(Trav. Stat. Wimereux), 9, p. 80, 1 pl. (1899);7a.J. Cecconi, “Sur l’Anchorina sagittata, &c.,”Arch. Protistenk.6, p. 230, 2 pls. (1905);8.H. Crawley, “Progressive Movement of Gregarines,”P. Ac. Philad.54, p. 4, 2 pls. (1902), alsoop. cit.57, p. 89 (1905);9.H. Crawley, “List of the Polycystid Gregarines of the U.S.,”op. cit.55, pp. 41, 632, 4 pls. (1903);10.L. Cuénot, “Recherches sur l’évolution et la conjugaison des Grégarines,”Arch. biol.17, p. 581, 4 pls. (1901);11.A. Laveran and F. Mesnil, “Sur quelques particularités de l’évolution d’une Grégarine et la réaction de la cellule-hôte,”C.R. Soc. Biol.52, p. 554, 9 figs. (1900);12.L. Léger, “Recherches sur les Grégarines,”Tabl. zool.3, p. i., 22 pls. (1892);13.L. Léger, “Contribution à la connaissance des Sporozoaires, &c.,”Bull. Sci. France, 30, p. 240, 3 pls. (1897);14.L. Léger, “Sur un nouveau Sporozoaire (Schizocystis), &c.,”C.R. Ac. Sci.131, p. 722 (1900);15.L. Léger, “La Reproduction sexuée chez les Ophryocystis,”t. c.p. 761 (1900);16.L. Léger, “Sur une nouvelle Grégarine (Aggregata coelomica,), &c.”op. cit.132, p. 1343 (1901);17.L. Léger, “La Reproduction sexuée chez les Stylorhynchus,”Arch. Protistenk.3, p. 304, 2 pls. (1904);18.L. Léger, “Etude surTaeniocystis mira(Léger), &c.,”op. cit.7, p. 307, 2 pls. (1906);19.L. Léger and O. Duboscq, “La Reproduction sexuée chezPterocephalus,”Arch. zool. exp.(N. et R.) (4) 1, p. 141, 11 figs. (1903);20.L. Léger and O. Duboscq, “Aggregata vagans, n. sp., &c.”t. c.p. 147, 6 figs. (1903);21.L. Léger and O. Duboscq, “Les Grégarines et l’épithélium intestinal, &c.,”Arch. parasitol.6, p. 377, 4 pls. (1902);22.L. Léger and O. Duboscq, “Nouvelles Recherches surles Grégarines, &c.,”Arch. Protistenk.4, p. 335, 2 pls. (1904);23.M. Lühe, “Bau und Entwickelung der Gregarinen,”t. c.p. 88, several figs. (1904);24.J. Nusbaum, “Über die ... Fortpflanzung einer ... Gregarine,Schaudinnella henleae,”Zeit. wiss. Zool.75, p. 281, pl. 22 (1903);25.F. Paehler, “Über die Morphologie, Fortpflanzung ... vonGregarina ovata,”Arch. Protistenk.4, p. 64, 2 pls. (1904);26.S. Prowazek, “Zur Entwickelung der Gregarinen,”op. cit., 1, p. 297, pl. 9 (1902);27.A. Schneider (Various memoirs on Gregarines),Tabl. zool.1 and 2 (1886-1892);28.H. Schnitzler, “Über die Fortpflanzung vonClepsydrina ovata,”Arch. Protistenk.6, p. 309, 2 pls. (1905);29.M. Siedlecki, “Über die geschlechtliche Vermehrung derMonocystis ascidiae,”Bull. Ac. Cracovie, p. 515, 2 pls. (1900);30.M. Siedlecki, “Contribution à l’étude des changements cellulaires provoquées par les Grégarines,”Arch. anat. microsc.4, p. 87, 9 figs. (1901);31.H. M. Woodcock, “The Life-Cycle ofCystobia irregularis, &c.,”Q.J.M. Sci.50, p. 1. 6 pls. (1906).

In those Gregarines (most intestinal forms) which become attached to an epithelial cell, the attachment occurs by means of a minute projection or beak (rostrum) at the anterior end of the sporozoite, which pushes its way into the cell, followed by the first part of the growing germ. This portion of the body increases in size much quicker at first than the rest (the extracellular part), more or less fills up the host-cell, and forms the well-developed epimerite or secondary attaching organella. The extracellular part of the Gregarine next grows rapidly, and a transverse septum is formed at a short distance away from (outside) the point where the body penetrates into the cell (fig. 6); this marks off the large deutomerite posteriorly (distally). Léger thinks that this partition most likely owes its origin to trophic considerations,i.e.to the slightly different manner in which the two halves of the young parasite (the proximal, largely intracellular part, and the distal, extracellular one) may be supposed to obtain their nutriment. In the case of the one half, the host-cell supplies the nutriment, in that of the other, the intestinal liquid; and the septum is, as it were, the expression of the conflicting limit between these two methods. Nevertheless, the present writer does not think that mechanical considerations should be altogether left out of account. The septum may also be, to some extent, an adaption for strengthening the body of the fixed parasite against lateral thrusts or strains, due to the impact of foreign bodies (food, &c.) in the intestine.

At the point where the body becomes actually intracellular, it is constricted, and this constriction marks off the epimerite (internally) from the middle portion (between this point and the septum), which is the protomerite. Further growth is restricted, practically, to the extracellular regions, and the epimerite often comes to appear ultimately as a small appendage at the anterior end of the protomerite. A Gregarine at this stage is known as a cephalont. Later on, the parasite breaks loose from the host-cell and becomes free in the lumen, the separation taking place at the constriction between the protomerite and the epimerite; the latter is left behind in the remains of the host-cell, the former becomes the anterior part of the free trophozoite.

In other Gregarines, however, those, namely, which pass inwards, ultimately becoming “coelomic,” as well as those which become entirely intracellular, no epimerite is ever developed, and, further, the body remains single or unseptate. These forms, which include, for instance,Monocystis(fig. 4),Lankesteria,Diplocystis, are distinguished, asAcephalinaorAseptata(Haplocyta,Monocystida), according to which character is referred to, from the others, termedCephalinaorSeptata(Polycystida).

The two sets of terms are not, however, completely identical or interchangeable, for there are a few forms which possess an epimerite, but which lack the division into protomerite and deutomerite, and are hence known asPseudomonocystida; this condition may be primitive (Doliocystis) or (possibly) secondary, the partition having in course of time disappeared. Again,Stenophorais a septate form which has become, secondarily, completely intracellular during the young stages, and, doubtless correlated with this, shows no sign of an epimerite.

1,Gregarina longa.

2,Sycia inopinata.

3,Pileocephalus heerii.

4,Stylorhynchus longicollis.

5,Beloides firmus.

6,Cometoides crinitus.

7,Geneiorhynchus monnieri.

8,Echinomera hispida.

9,Pterocephalus nobilis.

With regard to the epimerites themselves, they are of all variety of form and shape and need not be described in detail (fig. 7). In one or two cases, however, another variety of attaching organella is met with. Thus inPterocephalus, only the rostrum of the sporozoite penetrates into the host-cell, and no epimerite is formed. Instead, a number of fine root-like processes are developed from near the anterior end, which pass in between the host-cells (fig. 5) and thus anchor the parasite firmly. Similarly, in the curiousSchizogregarinae, the anterior end of the (unseptate) body forms a number of stiff, irregular processes, which perform the same function (fig. 8). It is to be noted that these processes are non-motile, and not in any way comparable to pseudopodia, to which they were formerly likened.

A very interesting and remarkable morphological peculiarity has been recently described by Léger (18) in the case of a new Gregarine,Taeniocystis. In this form the body is elongated and metamerically segmented, recalling that of a segmented worm, the adult trophozoites possessing numerous partitions or segments (each corresponding to the septum between the proto- and deuto-merite in an ordinary Polycystid), which divide up the cytoplasm into roughly equal compartments. Léger thinks only the deutomerite becomes thus segmented, the protomerite remaining small and undivided. The nucleus remains single, so that there is no question as to the unicellular or individual nature of the entire animal.

The general cytoplasm usually consists of distinct ectoplasm and endoplasm, and is limited by a membrane or cuticle (epicyte), secreted by the former. The cuticle varies considerably in thickness, being well developed in active, intestinalMinute structure.forms, but very thin and delicate in non-motile coelomic forms (e.g.Diplodina). In the former case it may show longitudinal striations. The cuticle also forms the hooks or spines of many epimerites. The ectoplasm usually shows (fig. 9A) a differentiation into two layers, an outer, firmer layer, clear and hyaline, the sarcocyte, and an inner layer, the myocyte, which is formed of a network of muscle-fibrillae (mainly longitudinal and transverse, fig. 9B). The sarcocyte alone constitutes the septum, traversing the endoplasm, in septate Gregarines. The myonemes are undoubtedly the agents responsible for the active “gregarinoid” movements (of flexion and contraction) to be observed in many forms. The peculiar gliding movements were formerly thought to be produced by the extrusion of a gelatinous thread posteriorly, but Crawley (8) has recently ascribed them to a complicated succession of wave-like contractions of the myocyte layer. This view is supported by the fact that certain coelomic forms, likeDiplodinaand others, which either lack muscle-fibrils or else show no ectoplasmic differentiation at all, are non-motile. The endoplasm, or nutritive plasm, consists of a semi-fluid matrix in which are embedded vast numbers of grains and spherules of various kinds and of all sizes, representing an accumulation of food-material which is being stored up prior to reproduction. The largest and most abundant grains are of a substance termed para-glycogen, a carbohydrate; in addition, flattenedlenticular platelets, of an albuminoid character, and highly-refringent granules often occur.

Fig. 9a.—Longitudinal section of a Gregarine in the region of the septum between protomerite and deutomerite.

Pr, Protomerite.

De, Deutomerite.

s, Septum.

en, Endoplasm.

sc, Sarcocyte.

c, Cuticle.

m,f, Myocyte fibrils (cut across).

g, Gelatinous layer.

Fig. 9b.—Gregarina munieri, showing the network of myocyte fibrillae.

The nucleus is always lodged in the endoplasm, and, in the septate forms, in the deutomeritic half of the body. It is normally spherical and always limited by a distinct nuclear membrane, which itself often contains chromatin. The most characteristic feature of the nucleus is the deeply-staining, more or less vacuolated spherical karyosome (consisting of chromatin intimately bound up with a plastinoid basis) which is invariably present. In one or two instances (e.g.Diplocystis schneideri) the nucleus has more than one karyosome. All the chromatin of the nucleus is not, however, confined to the karyosome, some being in the form of grains in the nuclear sap; and in some cases at any rate (e.g.Diplodina, Lankesteria) there is a well-marked nuclear reticulum which is impregnated with granules and dots of chromatin.

A sexual multiplication (schizogony) is only known certainly to occur in a few cases, one being in a Monocystid form, a species ofGonospora, which is for a long time intracellular (Caullery and Mesnil [4]), the rest among theSchizogregarinae, soLife-history.named for this reason, in which schizogonous fission takes place regularly during the free, trophic condition. Usually, the body divides up, by a process of multiple fission (fig. 10), into a few (up to eight) daughter-individuals; but in a new genus (Eleutheroschizon), Brasil (3) finds that a great number of little merozoites are formed, and a large amount of vacuolated cytoplasm is left over unused.

In the vast majority of Gregarines, however, the life-cycle is limited to gametogony and sporogony. A very general, if not indeed universal, prelude to gametogony is the characteristic and important feature of the order, known as association, the biological significance of which has only lately been fully brought out (see H. M. Woodcock [31]). In normal association, two individuals which are to be regarded as of opposite sex, come into close contact with each other and remain thus attached. The manner in which the parasites join varies in different forms; the association may be end-to-end (terminal), either by like or by unlike poles, or it may be side-to-side (lateral) (fig. 12). The couple (syzygy) thus formed may proceed forthwith to encystment and sporoblast-formation (Lankesteria, Monocystis), or may continue in the trophic phase for some time longer (Gregarina). In one or two instances (Zygocystis), association occurs as soon as the trophozoites become adult. This leads on to the interesting phenomenon of precocious association (neogamy), found in non-motile, coelomic Gregarines (e.g.Cystobia,DiplodinaandDiplocystis), in which the parasitism is most advanced. Woodcock (loc. cit.) has described and compared the different methods adopted to ensure a permanent union, and the degree of neogamy attained, in these forms. Here it must suffice to say that, in the extreme condition (seen, for instance, inDiplodina minchinii) the union takes place very early in the life-history, between individuals which are little more than sporozoites, and is of a most intimate character, the actual cytoplasm of the two associates joining. In such cases, there is absolutely nothing to indicate the “double” nature of the growing trophozoite, but the presence of the two nuclei which remain quite distinct.

There can be little doubt that, in the great majority, if not in all Gregarines, association is necessary for subsequent sporulation to take place;i.e.that the cytotactic attraction imparts a developmental stimulus to both partners, which is requisite for the formation of primary sporoblasts (gametes). This association is usually permanent; but in one or two cases (perhapsGonospora sp.) temporary association may suffice. While association has fundamentally a reproductive (sexual) significance, in some cases, this function may be delayed or, as it were, temporarily suspended, the cytotactic attraction serving meanwhile a subsidiary purpose in trophic life. Thus, probably, are to be explained the curious multiple associations and long chains of Gregarines (fig. 11) sometimes met with (e.g.Eirmocystis,Clepsydrina).

Encystment is nearly always double,i.e.of an associated couple. Solitary encystment has been described, but whether successful independent sporulation results, is uncertain; if it does, the encystment in such cases is, in all probability, only after prior (temporary) association. In the case of free parasites, a well-developed cyst is secreted by the syzygy, which rotates and gradually becomes spherical. A thick, at first gelatinous, outer cyst-membrane (ectocyst) is laid down, and then a thin, but firm internal one (endocyst). The cyst once formed, further development is quite independent of the host, and, in fact, often proceeds outside it. In certain coelomic Gregarines, on the other hand, which remain in very close relation with the host’s tissues, little or nothing of an encystment-process on the part of the parasites is recognizable, the cyst-wall being formed by an enclosing layer of the host (Diplodina).

The nuclear changes and multiplication which precede sporoblast-formation vary greatly in different Gregarines and can only be outlined here. In the formation of both sets of sexual elements (gametes) there is always a comprehensive nuclear purification or maturation. This elimination of a part of the nuclear material (to be distinguished as trophic or somatic, from the functional or germinal portion, which forms the sexual nuclei) may occur at widely-different periods. In some cases (Lankesteria,Monocystis), a large part of the original (sporont-) nucleus of each associate is at once got rid of, and the resulting (segmentation-) nucleus, which is highly-specialized, represents the sexual part. In other cases, again, the entire sporont-nucleus proceeds to division, and the distinction between somatic and germinal portions does not become manifest until after nuclear multiplication has continued for some little time, when certain of the daughter-nuclei become altered in character, and ultimately degenerate, the remainder giving rise to the sporoblast-nuclei (Diplodina,Stylorhynchus). Even after the actual sporoblasts (sex-cells) themselves are constituted, their nuclei may yet undergo a final maturation (e.g.Clepsydrina ovata); and inMonocystis, indeed, Brasil (2) finds that what is apparently a similar process is delayed until after conjugation and formation of the zygote (definitive sporoblast).

Nuclear multiplication is usually indirect, the mitosis being, as arule, more elaborate in the earlier than in the later divisions. The attraction-spheres are generally large and conspicuous, sometimes consisting of a well-developed centrosphere, with or without centrosomic granules, at other times of very large centrosomes with a few astral rays. In those cases where the karyosome is retained, and the sporont-nucleus divides up as a whole, however, the earliest nuclear divisions are direct; the daughter-nuclei being formed either by a process of simple constriction (e.g.Diplodina), or by a kind of multiple fission or fragmentation (GregarinaandSelenidium spp.). Nevertheless, the later divisions, at any rate inDiplodina, are indirect.

By the time nuclear multiplication is well advanced or completed, the bodies of the two parent-Gregarines (associates) have usually become very irregular in shape, and produced into numerous lobes and processes. While in some forms (e.g.Monocystis,Urospora,Stylorhynchus) the two individuals remain fairly separate and independent of each other, in others (Lankesteria) they become intertwined and interlocked, often to a remarkable extent (Diplodina). The sexual nuclei next pass to the surface of the processes and segments, where they take up a position of uniform distribution. Around each, a small area of cytoplasm becomes segregated, the whole often projecting as a little bud or hillock from the general surface. These uninuclear protuberances are at length cut off as the sporoblasts or gametes. Frequently a large amount of the general protoplasm of each parent-individual is left over unused, constituting two cystal residua, which may subsequently fuse; inDiplodina, however, practically the whole cytoplasm is used up in the formation of the gametes.

a, Undifferentiated gamete, attached to body of parent-individual.

b-d, Stages in development of motile male gamete.

e, Mature female gamete.

f,g, Stages in conjugation and nuclear union of the two elements.

h, Zygote (copula).

i, Spore, still with single nucleus and undivided sporoplasm.

The sporoblasts themselves show all gradations from a condition of marked differentiation into male and female (anisogamy), to one of complete equality (isogamy). Anisogamy is most highly developed inPterocephalus. Here, the male elements (microgametes) are minute, elongated and spindle-like in shape, with a minute rostrum anteriorly and a long flagellum posteriorly, and very active; the female elements (megagametes) are much larger, oblong to ovoid, and quite passive. InStylorhynchusthe difference between the conjugating gametes is not quite so pronounced (fig. 13), the male elements being of about the same bulk as the females, but pyriform instead of round, and possessing a distinct flagellum; a most interesting point about this parasite is that certain highly motile and spermatozoon-like male gametes are formed (fig. 13), which are, however, quite sterile and have acquired a subsidiary function. In other cases, again, the two kinds of element exhibit either very slight differences (Monocystis) or none (Urospora,Gonospora), in size and appearance, the chief distinction being in the nuclei, those of the male elements being smaller and chromatically denser than those of the females.

Lastly, inLankesteria,Gregarina,Clepsydrina,DiplocystisandDiplodinacomplete isogamy is found, there being no apparent difference whatever between the conjugating elements. Nevertheless, these forms are also to be regarded as instances of binary sexuality and not merely of exogamy; for it is practically certain that this condition of isogamy is derived from one of typical anisogamy, through a stage such as is seen inGonospora, &c. And, similarly, just as in all instances where the formation of differentiated gametes has been observed, the origin of the two conjugates is from different associates (parent-sporonts), and all the elements arising from the same parent are of the same sex, so it is doubtless the case here.

The actual union is brought about or facilitated by the well-known phenomenon termed thedanse des sporoblastes, which is due to various causes. In the case of highly-differentiated gametes (Pterocephalus), the actively motile microgametes rush about here and there, and seek out the female elements. InStylorhynchus, Léger has shown that the function of the sterile male gametes is to bring about, by their vigorous movements, themêlée sexuelle. In the forms where the gametes are isogamous or only slightly differentiated and (probably) not of themselves motile, other factors aid in producing the necessary commingling. Thus inGregarina sp.from the mealworm, the unused somata or cystal residua become amoeboid and send out processes which drive the peripherally-situated gametes round in the cyst; in some cases where the residual soma becomes liquefied (Urospora) the movements of the host are considered to be sufficient; and lastly, inDiplodina, owing to the extent to which the intertwining process is carried, if each gamete is not actually contiguous to a suitable fellow-conjugant, a very slight movement or mutual attraction will bring two such, when liberated, into contact.

An unusual modification of the process of sporoblast-formation and conjugation, which occurs inOphryocystis, must be mentioned. Here encystment of two associates takes place as usual; the sporont-nucleus of each, however, only divides twice, and one of the daughter-nuclei resulting from each division degenerates. Hence only one sporoblast-nucleus, representing a quarter of the original nuclear-material, persists in each half. Around this some of the cytoplasm condenses, the rest forming a residuum. The sporoblast or gamete thus formed is completely isogamous and normally conjugates with the like one from the other associate, when a single zygote results which becomes a spore containing eight sporozoites, in the ordinary manner. Sometimes, however, the septum between the two halves of the cyst does not break down, in which case parthenogenesis occurs, each sporoblast developing by itself into a small spore.

The two conjugating elements unite completely, cytoplasm with cytoplasm and nucleus with nucleus, to form the definitive sporoblast or zygote. The protoplasm assumes a definite outline, generally that of an ovoid or barrel, and secretes a delicate membrane, the ectospore. This subsequently becomes thickened, and often produced into rims, spines or processes, giving rise to the characteristic appearance of the Gregarine spore. Internal to the ectocyst, another, thinner membrane, the endocyst, is also laid down. These two membranes form the spore-wall (sporocyst). Meanwhile the contents of the spore have been undergoing division. By successive divisions, usually mitotic, the zygote-nucleus gives rise to eight daughter-nuclei, each of which becomes the nucleus of a sporozoite. Next, the sporoplasm becomes split longitudinally, around each nucleus, and thus eight sickle-shaped (falciform) sporozoites are formed. There is usually acertain amount of unused sporoplasm left over in the centre of the spore, constituting the sporal residuum. It is important to note that in all known Gregarines, with one exception, the number of sporozoites in the spore is eight; the exception isSelenidium, in many ways far from typical, where the number is half, viz. four.

Hitherto a variation from the general mode of spore-formation has been considered to occur in certain Crustacean Gregarines, theAggregatidaeand thePorosporidae. The spores of these forms have been regarded as gymnospores (naked), lacking the enveloping membranes (sporocyst) of the ordinary spores, and the sporozoites, consequently, as developed freely in the cyst. In the case of the first-named parasites, however, what was taken for sporogony has been proved to be really schizogony, and on other grounds these forms are, in the present writer’s opinion, preferably associated with the Coccidia (q.v.). With regard to thePorosporidae, also, it is quite likely that the gymnosporous cysts considered to belong to the GregarinePorospora(as known in the trophic condition) have really no connexion with it, but represent the schizogonous generation of some other form, similar toAggregata; in which case the true spores ofPorosporahave yet to be identified.

In the intestine of a fresh host the cysts rupture and the spores are liberated. This is usually largely brought about by the swelling of the residual protoplasm. Sometimes (e.g.Gregarina) long tubular outgrowths, known as sporoducts (fig. 15), are developed from the residual protoplasm, for the passage of the spores to the exterior.

The Gregarines are extremely numerous, and include severalClassification.families, characterized, for the most part, by the form of the spores (fig. 16). The specializedSchizogregarinaeare usually separated off from the rest as a distinct sub-order.

Sub-order I.—Schizogregarinae.

Forms in which schizogonic reproduction is of general occurrence during the extra-cellular, trophic phase. Three genera,Ophryocystis,SchizocystisandEleutheroschizon, different peculiarities of which have been referred to above. Mostly parasitic in the intestine or Malpighian tubules of insects. (In this type of parasite, as exemplified byOphryocystis, the body was formerly wrongly considered as amoeboid, and hence this genus was placed in a special order, theAmoebosporidia.)

a,Eirmocystis, Sphaerocystis, &c.

b,Echinomera, Pterocephalus, &c.

c,Gregarina, &c.

d,Beloides.

e,Ancyrophora.

f,Stylorhynchidae(type of).

g,Menosporidae.

h,Gonospora terebellae.

i,Ceratospora.

k,Urospora synaptae.

Sub-order II.—Eugregarinae.

Schizogony very exceptional, only occurring during the intracellular phase, if at all. Gregarines fall naturally into two tribes, described as cephalont and septate, or as acephalont and aseptate (haplocytic), respectively. In strictness, however, as already mentioned, these two sets of terms do not agree absolutely, and whichever set is adopted, the other must be taken into account in estimating the proper position of certain parasites. Here the cephalont or acephalont condition is regarded as the more primary and fundamental.

Tribe A.—Cephalina(practically equivalent toSeptata).

Save exceptionally, the body possesses an epimerite, at any rate during the early stages of growth, and is typically septate. Mostly intestinal parasites of Arthropods.

The chief families, with representative genera, are as follows:Porosporidae, withPorospora gigantea, at present thought to be gymnosporous;Gregarinidae(Clepsydrinidae), withGregarina,Clepsydrina,Eirmocystis,Hyalospora,Cmenidospora,Stenophora;Didymophyidae, withDidymophyes;Dactylophoridae, withDactylophorus,Pterocephalus,Echinomera,Rhopalonia;ActinocephalidaewithActinocephalus,Pyxinia,Coleorhynchus,Stephanophora,Legeria,Stictospora,Pileocephalus,Sciadophora;AcanthosporidaewithAcanthospora,Corycella,Cometoides;MenosporidaewithMenospora,Hoplorhynchus;Stylorhynchidae, withStylorhynchus,Lophocephalus;DoliocystidaewithDoliocystis; andTaeniocystidae, withTaeniocystis. The curious genusSelenidiumis somewhat apart.

Tribe B.—Acephalina(practically equivalent toAseptata,Haplocyta).

The body never possesses an epimerite and is non-septate. Chiefly coelomic parasites of “worms,” Holothurians and insects.

TheAseptatahave not been so completely arranged in families as theSeptata. Léger has distinguished two well-marked ones, but the remaining genera still want classifying more in detail. Fam.Gonosporidae, withGonospora,Diplodina; andUrosporidae, withUrosopora,Cystobia,Lithocystis,Ceratospora; the generaMonocystis,Diplocystis LankesteriaandZygocystisprobably constitute another;Pterosporaand, again,Syncystisare distinct; lastly, certain forms,e.g.Zygosoma,Anchora(Anchorina), are incompletely known.

There remains for mention the remarkable parasite, recently described by J. Nusbaum (24) under the appropriate name ofSchaudinnella henleae, which inhabits the intestine ofHenlea leptodera. Briefly enumerated, the principal features in the life-cycle are as follows. The young trophozoites (aseptate) are attached to the intestinal cells, but practically entirely extracellular. Association is very primitive in character and indiscriminate; it takes place indifferently between individuals which will give rise to gametes of the same or opposite sex. Often it is only temporary; at other times it is multiple, several adults becoming more or less enclosed in a gelatinous investment. Nevertheless, in no case does true encystment occur, the sex-cells being developed practically free. The female gametes are large and egg-like; the males, minute and sickle-like, but with no flagellum and apparently non-motile. While many of the zygotes (“amphionts”) resulting from copulation pass out to the exterior, to infect a new host, others, possessing a more delicate investing-membrane, penetrate in between the intestinal cells, producing a further infection (auto-infection). Numerous sporozoites are formed in each zygote. It will be seen thatSchaudinnellais a practically unique form. While, on the one hand, it recalls the Gregarines in many ways, on the other hand it differs widely from them in several characteristic features, being primitive in some respects, but highly specialized in others, so that it cannot be properly included in the order.Schaudinnellarather represents a primitive Ectosporan parasite, which has proceeded upon a line of its own, intermediate between the Gregarines and Coccidia.

Bibliography.—Among the important papers relating to Gregarines are the following:1.A. Berndt, “Beitrag zur Kenntnis der ... Gregarinen,”Arch. Protistenk.I, p. 375, 3 pls. (1902);2.L. Brasil, “Recherches sur la reproduction des Grégarines monocystidées,”Arch. zool. exp.(4) 3, p. 17, pl. 2 (1905), andop. cit.4, p. 69, 2 pls. (1905);3.L. Brazil, “Eleutheroschizon duboscqi, parasite nouveau, &c.,”op. cit.(N. et R.) (4), p. xvii., 5 figs. (1906);4.M. Caullery and F. Mesnil, “Sur une Grégarine ... présentant ... une phase de multiplication asporulée,”C.R. Ac. Sci.126, p. 262 (1898);5.M. Caullery and F. Mesnil, “Le Parasitisme intracellulaire des Grégarines,”op. cit.132, p. 220 (1901);6.M. Caullery and F. Mesnil, “Sur une mode particulière de division nucléaire chez les Grégarines,”Arch. anat. microsc.3, p. 146, 1 pl. (1900);7.M. Caullery and F. Mesnil, “Sur quelques parasites internes des Annélides,”Misc. biol.(Trav. Stat. Wimereux), 9, p. 80, 1 pl. (1899);7a.J. Cecconi, “Sur l’Anchorina sagittata, &c.,”Arch. Protistenk.6, p. 230, 2 pls. (1905);8.H. Crawley, “Progressive Movement of Gregarines,”P. Ac. Philad.54, p. 4, 2 pls. (1902), alsoop. cit.57, p. 89 (1905);9.H. Crawley, “List of the Polycystid Gregarines of the U.S.,”op. cit.55, pp. 41, 632, 4 pls. (1903);10.L. Cuénot, “Recherches sur l’évolution et la conjugaison des Grégarines,”Arch. biol.17, p. 581, 4 pls. (1901);11.A. Laveran and F. Mesnil, “Sur quelques particularités de l’évolution d’une Grégarine et la réaction de la cellule-hôte,”C.R. Soc. Biol.52, p. 554, 9 figs. (1900);12.L. Léger, “Recherches sur les Grégarines,”Tabl. zool.3, p. i., 22 pls. (1892);13.L. Léger, “Contribution à la connaissance des Sporozoaires, &c.,”Bull. Sci. France, 30, p. 240, 3 pls. (1897);14.L. Léger, “Sur un nouveau Sporozoaire (Schizocystis), &c.,”C.R. Ac. Sci.131, p. 722 (1900);15.L. Léger, “La Reproduction sexuée chez les Ophryocystis,”t. c.p. 761 (1900);16.L. Léger, “Sur une nouvelle Grégarine (Aggregata coelomica,), &c.”op. cit.132, p. 1343 (1901);17.L. Léger, “La Reproduction sexuée chez les Stylorhynchus,”Arch. Protistenk.3, p. 304, 2 pls. (1904);18.L. Léger, “Etude surTaeniocystis mira(Léger), &c.,”op. cit.7, p. 307, 2 pls. (1906);19.L. Léger and O. Duboscq, “La Reproduction sexuée chezPterocephalus,”Arch. zool. exp.(N. et R.) (4) 1, p. 141, 11 figs. (1903);20.L. Léger and O. Duboscq, “Aggregata vagans, n. sp., &c.”t. c.p. 147, 6 figs. (1903);21.L. Léger and O. Duboscq, “Les Grégarines et l’épithélium intestinal, &c.,”Arch. parasitol.6, p. 377, 4 pls. (1902);22.L. Léger and O. Duboscq, “Nouvelles Recherches surles Grégarines, &c.,”Arch. Protistenk.4, p. 335, 2 pls. (1904);23.M. Lühe, “Bau und Entwickelung der Gregarinen,”t. c.p. 88, several figs. (1904);24.J. Nusbaum, “Über die ... Fortpflanzung einer ... Gregarine,Schaudinnella henleae,”Zeit. wiss. Zool.75, p. 281, pl. 22 (1903);25.F. Paehler, “Über die Morphologie, Fortpflanzung ... vonGregarina ovata,”Arch. Protistenk.4, p. 64, 2 pls. (1904);26.S. Prowazek, “Zur Entwickelung der Gregarinen,”op. cit., 1, p. 297, pl. 9 (1902);27.A. Schneider (Various memoirs on Gregarines),Tabl. zool.1 and 2 (1886-1892);28.H. Schnitzler, “Über die Fortpflanzung vonClepsydrina ovata,”Arch. Protistenk.6, p. 309, 2 pls. (1905);29.M. Siedlecki, “Über die geschlechtliche Vermehrung derMonocystis ascidiae,”Bull. Ac. Cracovie, p. 515, 2 pls. (1900);30.M. Siedlecki, “Contribution à l’étude des changements cellulaires provoquées par les Grégarines,”Arch. anat. microsc.4, p. 87, 9 figs. (1901);31.H. M. Woodcock, “The Life-Cycle ofCystobia irregularis, &c.,”Q.J.M. Sci.50, p. 1. 6 pls. (1906).

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