devoured by Polyphemus) made his escape by clinging to the bellies of the sheep let out to pasture. Euripides in the Cyclops essentially follows the Homeric account. A later story associates Polyphemus with Galatea (see ACIS).

Homer, Odyssey, ix.; Ovid, Metam. xiii. 749; Theocritus xi. See W. Grimm, Die Sage von Polyphem. (1857); G. R. Holland, in Leipziger Studien (1884), vii. 139-312.

POLYPODIUM, in botany, a large genus of true ferns (q.v.), widely distributed throughout the world, but specially developed in the tropics. The name is derived from Gr. Toλús, many, and Tódov, a little foot, on account of the foot-like appearance of the rhizome and its branches. The species differ greatly in size and general appearance and in the character of the frond; the sori or groups of spore-cases (sporangia) are borne on the back of the leaf, are globose and naked, that is, are not covered with a membrane (indusium) (see fig. 1). The common polypody (fig. 2) (P. vulgare) is widely diffused in the British Isles, where it is found on walls, otom

banks, trees, &c.; the creep-dor bathjge
ing, densely-scaly rootstockle Winorteig
bears deeply pinnately cut
fronds, the fertile ones bear-
ing on the back the bright
yellow lenaked groups of
sporangia (sori). It is also
known as adder's foot,
golden maidenhair and
wood-fern, and is the oak-
fern of other old herbals.
deodt HA atong di

membrane. A polypus or polypoid tumour may belong to any variety of tumour, either simple or malignant. The most common variety is a polypus of the nose of simple character and easily removed. Polypi are also met with in the ear, larynx, uterus, bladder, vagina, and rectum. (See TUMOUR.)

POLYTECHNIC (Gr. Tolus, many, and réxvn, an art), a term which may be held to designate any institution formed with a view to encourage or to illustrate various arts and sciences. It has, however, been used with different applications in several European countries. In France the first école polytechnique was founded by the National Convention at the end of the 18th century, as a practical protest against the almost exclusive devotion to literary and abstract studies in the places of higher learning. The institution is described as one "où l'on instruit les jeunes gens, destinés à entrer dans les écoles spéciales d'artillerie, du génie, des mines, des ponts et chaussées, créé en 1794 sous le nom d'école centrale des travaux publiques, et en 1795 sous celui qu'elle porte aujourd'hui" (Littré). In Germany there are nine technical colleges which, in like manner, have a special and industrial rather than a general educational purpose. In Switzerland, the principal educational institution, which is not maintained or administered by the communal authorities, but is non-local and provided by the Federal government, is the Polytechnikum at Zurich. In all the important towns of the Federation there are trade and technical schools of a more or less special character, adapted to the local industries; e.g. schools for silk-weaving, wood-carving, watchmaking, or agriculture. But the Zurich Polytechnikum has a wider and more comprehensive range of work. It is a college designed to give instruction and practical training in those sciences which stand in the closest relation to manufactures and commerce and to skilled industry in general and its work is of university rank..

To the English public the word polytechnic has only recently become familiar, in connexion with some London institutions of an exceptional character. In the reign of William The First IV. there was an institution in London called after Polytechnics the name of his consort-" The Adelaide Gallery ≫ in England. -and devoted rather to the display of new scientific inventions and curiosities than to research or to the teaching of science. It enjoyed an ephemeral popularity, and was soon imitated by an institution called the Polytechnic in Regent Street, with a somewhat more pretentious programme, a divingbell, electrical and mechanical apparatus, besides occasional illustrated lectures of a popular and more or less recreative character. In the popular mind this institution is inseparably associated with "Professor" Pepper, the author of The Boy's Playbook of Science and of Pepper's Ghost. Both of these

FIG. 2.-Polypodium vulgare, common polypody (about nat. institutions, after a few years of success, failed financially; and size). in 1880 Mr Quintin Hogg, an active and generous philan1. Group of spore-cases (sorus) on thropist, purchased the disused building in Regent Street, and back of leaf. reopened it on an altered basis, though still retaining the name of Polytechnic, to which, however, he gave a new significance. He had during sixteen years been singularly successful in gathering together young shopmen and artisans in London in the evenings and on Sunday for religious and social intercourse, and in acquiring their confidence. But by rapid degrees his enterprise, which began as an evangelistic effort, developed into an educational institution of a novel and comprehensive character, with classes for the serious study of science, art, and literature, a gymnasium, library, reading circles, laboratories for physics and chemistry, conversation and debating clubs, organized country excursions, swimming, rowing, and natural history societies, a savings bank, and choral singing, besides, religious services, open to all the members, though not obligatory for any. The founder, who from the first took the closest personal interest in the students, well describes his own aims: "What we wanted to develop our institute into was a

There are a large number of varieties, differing chiefly in the form and division of the pinnae; var. cambricum (originally found in Wales) has the pinnae themselves deeply cut into narrow segments; var. cornubiense is a very elegant plant with finely-divided fronds; var. cristatum is a handsome variety with fronds forking at the apex and the tips of all the pinnae crested and curled. P. dryopteris, generally known as oakfern, is a very graceful plant with delicate fronds, 6 to 12 in. long, the three main branches of which are themselves pinnately divided; it is found in dry, shady places in mountain districts in Great Britain, but is very rare in Ireland. P. phegopteris (beechfern) is a graceful species with a black, slender root-stock, from which the pinnate fronds rise on long stalks, generally about 12 in. long, including the stalk; it is characterized by having the lower pinnae of the frond deflexed; it is generally distributed in Britain, though not common. Many other species from different parts of the world are known in green-place which should recognize that God had given man more than house cultivation.

POLYPUS, a term signifying a tumour which is attached by a narrow neck to the walls of a cavity lined with mucous

one side to his character, and where we could gratify any reasonable taste, whether athletic, intellectual, spiritual or social. The success of this effort was remarkable. In the first winter.

6800 members joined, paying fees of 35. per term, or 10s. 6d. per | year; and the members steadily increased, until in 1900 they reached a total of 15,000 The average daily attendance is 4000; six hundred classes in different grades and subjects are held weekly; and upwards of forty clubs and societies have been formed in connexion with the recreative and social departments. The precedent thus established by private initiative has since been followed in the formation of the public institutions which, under the name of "Polytechnics," have become Institutions so prominent and have exercised such beneficent influence among the working population of London. Class The principal resources for the foundation and maintenance of these institutions have been derived from two funds-that administered under the City Parochial Charities Act of 1883, and that furnished by the London County Council, at first under the terms of the Local Taxation (Customs and Excise) Act of 1890, and the Technical Instruction Act 1889, but since the 1st of May 1904 under the Education Act 1902, as applied to London by the act of 1903. More detailed reference to these two acts seems to be necessary in this place.

e/th

Grants to the London Polytechnics during the Session 1906-1907.

Battersea Polytechnic
Birkbeck College.
Borough Road Polytechnic
City of London College
East London College
Northampton Institute
Regent Street Polytechnic
Northern Polytechnic
South-Western Polytechnic
Woolwich Polytechnic
Sir John Cass's Institute.

The Goldsmiths' Institute at New Cross owed its existence | one-third of the population of London were not natives. They and its annual maintenance to the generous initiative of the ancient city gild whose name it bore. It was therefore entirely independent of pecuniary subsidy from any other public body. In the year 1900 the number of class entries to this institute was 7574. In 1904 the goldsmiths' company presented the premises, together with an annual subsidy, to the university of London for the purposes of a training college for teachers, so that from that date it ceased to be one of the London polytechnics, although, pending the provision of other premises, many of the technical evening classes have been continued under the London County Council by permission of the university with the approval of the company. The clothworkers' company has also contributed £18,000 to the Northern Polytechnic at Holloway.

In all these institutions the general aims have been practically the same, although special features have been differentiated Aims and in order to meet the local needs and the wishes of Methods. the inhabitants. In all there are laboratories and lecture rooms, trade classes, art studios, gymnasia, provision for manual training and domestic economy and applied science. In nearly all, at first, mechanical and manual instruction were the prominent objects in view, partly owing to the conditions under which grants were made by the science and art department. But of late increased attention has been paid year by year to literary and humaner studies, and to general mental cultivation, pursued pari passu with technical and scientific training. The aid of the London organization for university extension, now a department of the university, has been especially serviceable in providing courses of lectures and classes in literary subjects at nearly all the polytechnics. As subsidiary to their main work, some of them have established junior continuation schools, with a view to provide suitable instruction for scholars who have left the public elementary schools and are not yet prepared to enter the technical and trade classes. Although the workshops and the classes for artisans are used chiefly in the evenings, there is an increasing number of day students: e.g. at the Northampton Polytechnic Institute in Clerkenwell there is a very important day school of engineering conducted on the "sandwich system," the students entering engineering works for the summer months and returning to the polytechnic for the winter session; at the Battersea Polytechnic there is a very important training college for teachers of domestic economy; at Regent Street there are day schools in engineering, architecture, photo-process and carriage-building; at the South-Western Polytechnic there are important schools of mechanical and electrical engineering and a training college for women teachers of physical exercises; at the Northern Polytechnic, as at Battersea, there is a training college for teachers of domestic economy, and there are departments of commerce and of physics and chemistry, while the Woolwich Polytechnic receives in the daytime, by special arrangement with the war office, a large number of engineering apprentices employed in the arsenal. In short, the schemes of the several institutions are so elastic that the governing bodies are at liberty to open any classes or to try any educational or recreative experiment for which they can find a genuine local 1. demand. The total number of scholars in the polytechnics and their branch institutions is variously estimated at from 40,000 to 50,000, and the total number of regular scholars in the evening schools of the council does not exceed 100,000. These figures may be usefully compared with the census returns, which show that within the metropolitan area there are 704,414 persons between the ages of thirteen and twentyone. It is a noteworthy fact that, whereas in the population statistics for the whole of England and Wales the number at each year of age is regularly diminished by death from eight years onwards, there is a steady increase in London, year by year, from fourteen up to the age of thirty. This fact is owing to the constant immigration of young men and women from the provinces to the metropolis. The census commissioners in their report for 1901 (p. 15) computed that more than

show also that, if all England and Wales be taken together, the number of persons between twenty and twenty-one is less by 12.8% than the number between thirteen and fourteen; but that, taking London alone, the number of persons between twenty and twenty-one is greater by 14.4% than the number between thirteen and fourteen. Hence, the proportion of the inhabitants who are of an age to benefit by polytechnics and continuation schools is in London exceptionally large. It would not be right for Londoners to complain that there is thus cast upon them the duty of providing suitable instruction for so many immigrants, for if the great city drains the rural districts of some of their best brain and muscle, she gains much from their industry and productive power. The figures, however, point to the necessity for taking every means possible to raise the standard, both physical and intellectual, of the London boy. The immigration into London of youths and young men means to a great extent the substitution of the provincially trained improver or artisan for the less fit London boy, who consequently falls into the ranks of the unskilled, then of the unemployed and ultimately of the unemployable. But it follows from the particulars thus given that neither the supply of suitable provision for mental improvement and rational recreation for the wage-earning classes, nor the demand for such provision on the part of the workers themselves is commensurate with the moral and intellectual needs of a community of nearly seven millions of people (four and a half millions within the administrative county). The provision in evening schools, institutes, classes and polytechnics is still in some respects far inferior to that which is to be found in most German and Swiss towns, and needs to be greatly increased. In matters relating to the higher life, demand does not always precede supply; it is simply which is needed not only to satisfy the public demand, but to create it. As new and well-devised opportunities for mental culture are placed within reach, they will be more and more appreciated, new and healthier appetites will be stimulated, the art of employing leisure wisely and happily will be more systematically studied, and the polytechnics will become still more important centres of civilizing and educating influence than they have hitherto been.

In particular, the reconstituted university of London has been placed in new and most helpful relation to the best of the polytechnics. By the statutes the senate of the university is empowered to include in the list of " schools of the university " all institutions which are duly equipped and able to furnish suitable instruction of an advanced and scholarly type; and also to recognize all thoroughly qualified professors in their several faculties and subjects as teachers of the university," although some of their classes may meet in the evening only, and no student is to be prevented from taking a degree as an internal student of the university solely because he can attend classes only in the evening. There is thus a way open for the due recognition of the polytechnics as part of the teaching machinery of the university, and for the admission of the best students as undergraduates, with all the rights of internal students. The great possibilities of the metropolitan university under its new conditions were at first hardly revealed or accurately foreseen. But there were during the session 1906-1907 no less than eighty-six recognized "teachers of the university" on the staffs of the London polytechnics and more than 750 students who were working for London University degrees in the polytechnic classes. There is no reason to fear that the recreative, social, manual and industrial training, to which at first the special attention of the founder of the Regent Street Polytechnic was directed, will suffer from a fuller expansion of the academic and literary side of " polytechnic " life. Rather it may be hoped that the due co-ordination of the practical with the purely intellectual purposes of these institutions will serve to give to all the students, whatever their future destination may be, a truer and broader conception of the value of mental culture for its own sake.

See also a paper by Mr Sidney Webb, The London Polytechnic | fied' walls, the external part of the introvert being closed during Institutes, in the second volume of special reports on educational retraction by a membranous collar. Zooecia either arising from subjects (1898) issued by the Education Department; the Report a stolon, without lateral connexion with one another, or laterally of the Central Governing Body of the London Parochial Charities; united to form sheets. Alcyonidium, Flustrella, Bowerbankia the Annual Reports of the London County Council; the Polytechnic (fig. 3), Farrella, Victorella, Paludicella. Magazine, published from time to time at the institute in Regent Street; and various memoirs and papers contained in the Proceedings of the International Congress on Technical Education (1897), especially two-that by Mr Quintin Hogg, detailing his own early experience in founding the first polytechnic, and that of Dr William Garnett, then secretary of the Technical Education Board.

(J. G. F.; W. G.)

POLYXENA, in Greek legend, daughter of Priam, king of Troy, and Hecuba. She had been betrothed to Achilles, who was slain by Paris in the temple of Apollo Thymbraeus, where the marriage was to have been celebrated (Hyginus, Fab. 110). The shade of Achilles afterwards appeared to the returning Greeks in the Thracian Chersonese and demanded the sacrifice of Polyxena, who was put to death by Neoptolemus, son of Achilles, on his father's grave (Ovid, Metam. xiii. 440 sqq.). The tragic story is the subject of the Hecuba of Euripides, the Troades of Seneca and the Polyxena of Sophocles, of which only a few fragments remain. According to Philostratus (Heroica, 20, 18), Polyxena fled to the Greeks after the murder of Achilles and committed suicide on his tomb.

POLYZOA, in zoology, a term (introduced by J. V. Thompson, 1830) synonymous with Bryozoa (Ehrenberg, 1831) for a group commonly included with the Brachiopoda in the Molluscoidea (Milne Edwards, 1843). The correctness of this association is questionable, and the Polyzoa are here treated as a primary division or phylum of the animal kingdom. They may be defined as aquatic animals, forming colonies by budding; with ciliated retractile tentacles and a U-shaped alimentary canal. The phylum is subdivided as follows.

Class I. ENTOPROCTA (Nitsche). Lophophore circular, including both mouth and anus. Tentacles infolded, during

retraction, into a vestibule which can be
closed by a sphincter. Body-wall not
calcified, body-cavity absent. Definite
excretory organs present. Reproductive
organs with ducts leading to the vesti-
bule. Zooids possessing a high degree
of individuality. Loxosoma Pedicellina
(fig. 1), Urnatella.

Class II. ECTOPROCTA (Nitsche).
Lophophore circular or horseshoe
shaped, including the mouth but not
the anus. Tentacles retractile into an

(After Hincks.)

J

(After Hincks.) FIG. 4.-Zooecia of Umbonulo pavonella, showing a pair of minute avicularia on either side of the orifice of each zooecium.

FIG. 3. Part of a branch of Bowerbankia pustulosa, showing the thread-like stolon from which arise young and mature zooecia. The tentacles are expanded in some of the latter. Membraniporella, Cribrilina, Cellaria, Micropora, Selenaria, Umbonula (fig. 4), Lepralia, Schizoporella, Cellepora, Mucronella, Smittia, Retepora, Calenicella, Microporella, Adeona.

Order 2. PHYLACTOLAEMATA (Allman).-Lophophore horse-shoe shaped, or in Fredericella circular. Mouth guarded by an epistome. Body-cavities of zooids continuous with one another. Body-wall uncalcified and muscular. Reproduction sexual and by means of "statoblasts," peculiar internal buds protected by a chitinous shell. Fredericella, Plumatella (fig. 5), Lophopus, Cristatella, Pectinatella.

introvert ("tentacle-sheath "). Body-
wall membranous or calcified, body-
cavity distinct. Specific excretory
organs absent, with the doubtful excep-
tion of the Phylactolaemata. Repro-Fredericella,
ductive organs not continuous with ducts.
Zooids usually connected laterally with
their neighbours.

Order 1. GYMNOLAEMATA (Allman).-
(After van Beneden.) Lophophore circular, with no epistome.
FIG. 1.-Part of the Body-cavities of zooids not continuous
creeping stolon, with with one another. Body-wall not muscular.
zooids, of Pedicellina Sub-order 1. TRE POSTOMATA (Ulrich);
belgica.
Fossil.-Zooecia, long and coherent, pris-
a, c, Stalks of zooids matic or cylindrical, with terminal orifices,
of different ages; b, their wall thin and simple in structure
proximally, thickened and complicated
distally. Cavity of the zooecium subdivided
by transverse diaphragms, most numerous in the distal portion.
Orifices of the zooecia often separated by pores (mesopores).
Sub-order 2. CRYPTOSTOMATA (Vine); Fossil.-Zooecia usually
short. Orifice concealed at the bottom of a vestibular shaft, sur-
rounded by a solid or vesicular calcareous deposit.

bud.

Sub-order 3. CYCLOSTOMATA (Busk).-Zooecia prismatic or cylindrical, with terminal, typically circular orifice, not protected by any special organ. The ovicells are modified zooecia, and contain numerous embryos which in the cases so far investigated arise by fission of a primary embryo developed from an egg. Crisia (fig. 2), Tubulipora, Hornera, Lichenopora.

Hatschek (1888) treated the Entoprocta as a division of his group Scolecida, characterized by the possession of a primary body-cavity and of protonephridia; while he placed the Ectoprocta, with the Phoronida and Brachiopoda, in a distinct group, the Tentaculata. Against this view may be urged the essential similarity between the processes of budding in Entoprocta and Ectoprocta (cf. Seeliger, Zeitschr. wiss. Zool. xlix. 168; 1., 560), and the resemblances in the development of the two classes.

Of the forms above indicated there is no palaeontological evidence with regard to the Entoprocta. The Trepostomata are in the main Palaeozoic, although Heteropora, of which recent species exist, is placed by Gregory in this division. The Cryptostomata are also Palaeozoic, and include the abundant and widely-distributed genus Fenestella. The Cyclostomata are numerous in Palaeozoic rocks, but attained a specially predominant position in the Cretaceous strata, where they are represented by a profusion of genera and species; while they still survive in considerable numbers at the present day. The Ctenostomata are ill adapted for preservation as fossils, though remains referred to this group have been

1 Calcareous spicules have been described by Lomas in Alcyoni

Sub-order & CTENOSTOMATA (Busk).-Zooccia with soft uncalci- I dium gelatinosum.