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particles, and deposits in a regular oblique or spiral series, and which are cemented together by a special secretion. The urceolus serves as a defence, as the animal can by contracting its stalk withdraw itself entirely within the tube.
Locomotor Organs.—While, as mentioned above, several genera or individual species present long spines, these become movable, and may be spoken of as appendages, in two genera only. In Polyarthra (fig. 1, E, F) there are four groups of processes or plumes placed at the sides of
Fro. 2.-Floseularia appendiculata. A and B represcnt the same animal, some of the organs being shown in one figure and some in the other. oc, eye-spots; 9, nerve ganglion; p, pharynx (the mouth should be shown opening opposite the letter); ma, the mastax; e, cosophagus; ot, stomach; a, anus, opening the cloaca; gl, mucous glands in the pseudopodium; n, nephridia; f, flame-cells; b!, contractile vesicle; m, n, rauscles. the body, each of which groups can be separately moved up and down by means of muscular fibres attached to their bases, which project into the body. The processes themselves are unjointed and rigid. In Pedalion (fig. 3), a remarkable form discovered by Dr C. J. Hudson in 1871 (12, 18, 14, and 15), and found in numbers several times since, these appendages have acquired a new and quite special development. They are six in number. The largest is placed ventrally at some distance below the mouth. Its free extremity is a plumose fan-like expansion (fig. 3, A, a, and B). It is (in common with the others) a hollow process into which run two pairs of broad, coarsely transversely striated muscles. Each pair has a single insertion on the inner wall—the one pair near the free extremity of the limb, the other near its attachment; the bands run up, one of each pair on each side and run right round the body forming an incomplete muscular girdle, the ends approximating in the median dorsal, line. Below this point springs the large median dorsal limb, which termin: ates in groups of long setae. It presents a single pair of muscles attached along its inner wall which run up and form a muscular girdle round the body in its posterior third. On eaeh side is attached a superior dorso-lateral and an inferior ventro-lateral appendage, each with a fanlike plumose termination consisting of compound hairs, found elsewhere only among the Crustacea; each of these
is moved by muscles running upwards towards the neck and arising immediately under the trochal disk, the inferior ventro-lateral pair also presenting muscles which-form a girdle in the hind region of the body. Various other muscles are present: there are two complete girdles in the neck region immediately behind the mouth; there are also muscles which move the hinder region of the body. In addition to these the body presents various processes which are perhaps some of them unrepresented in other Rotifers. In the median dorsal line immediately below the trochal disk there is a short conical process presenting a pair of muscles which render it capable of slight movement. From a recess at the extremity of this process spring a group of long setose hairs the bases of which are connected with a filament probably nervous in nature. This doubtless represents a structure found in man
Rotifers, and variously known as the “calcar,” “siphon,” “tentaculum,” or “antenna.” This calcar is double in Tubicolaria and Melicerta. It is very well developed in the genera Rotifer, Philodina, and others, and is, when so developed, slightly retractile. It appears to be represented in many forms by a pit or depression set with hairs. The calcar has been considered both as an intromittent organ and a respiratory tube for the admission. of water. It is now, however, universally considered to be sensory in nature. Various forms present processes in other parts
Fro. 3.-Pedalion mira. A. Lateral surface view of an adult female : a, median ventral appendage; b, median dorsal appendages, c, inferior ventiolateral appendage; d, superior dorso-lateral appendage ; f, dorsal sense-organ (calcar) ; g, “chin;" x, cephalotroch. B, lateral view, showing the viscera : oc, ey: spots; n, nephridia; e, ciliated processes, probably serving for attachment; other 'letters as above. C, ventral view: 3', cephaloteoch; 4. branchiotroch; other letters as above. D, ventral view, showing the musculature (cf. text). E, dorsal view of a male: a, lateral appendages; b, dorsal appendage. F, lateral vicw of a male. G, enlarged view of the sense-organ marked f. H, enlarged view of the median ventral appendage. (All after Hudson.)
of the body which have doubtless a similar function, e.g., Microcodon (fig. 1, D, s) with its pair of lateral organs. Pedalion presents a pair of ciliated processes, in the posterior region of the body (fig. 3, B, 9, and B, e), which it can apparently use as a means of attachment; Dr Hudson states that he has seen it anchored by those and swimming round and round in a circle. They possibly represent the flaps found on the tail of other forms. Pedalion also has a small ciliated muscular process (fig. 3, A, 9) placed immediately below the mouth, and termed a “chin,” which appears to be merely a greater development of a sort of lower lip which occurs in many Rotifers.
Muscular System.—All the Rotifera present a muscular system which is generally very well developed. Transverse striation occurs among the fibres to a varying extent, being well marked in cases where the muscle is much used. The muscles which move the body as a whole are arranged as circular and lorgitudinal series, but they are arranged in special groups and do not form a comlete layer of the body-wall as in the various worms. Some of the i. muscles are specially developed in connexion with the tail or pedicle. Other muscles are developed in connexion with special systems of organs,—the trochal disks, the jaw apparatus, and the reproductive system. The muscles in connexion with the trochal disk serve to protrude or withdraw it, and to move it about, when extruded, in various directions. The protrusion is probably, however, generally effected by the elasticity of the integument coming into play during the relaxation of the retractor muscles, and by a #. contraction of the body wall. The tentaculiferous apparatus of Polyzoa and Gephyrsa is protruded in the same manner. Trochal Disk.-This structure is the peculiar characteristic of the class. It is homologous with the ciliated bands of the larvae of Echinoderms, Chopods, Molluscs, &c., and with the tentaculiferous apparatus of Polyzoa and Gephyrea, and has been termed in common with these a “velum.” This velum presents itself in various stages of complexity. It is found as a single circum-oral ring (pilidium), as a single prae-oral ring (Chaetopod larvae), or as a single prae-oral ring coexisting with one or more post-oral rings (Chaetopod larvae, Holothurian larvae). We may here assume that the ancestral condition was a single circum-oral ring associated with a terminal mouth and the absence of an anus, and that the existence of other rings posterior to this is an expression of metameric segmentation, i.e., a repetition of similar parts. With the development of a prostomiate condition a certain change necessarily takes lace in th. position of this band: a portion of it comes to lie [...iii; but it may still remain a single band, as in the larva of many Echinoderms. How have the other above-mentioned conditions of the velum come about? How has the prae-oral band been developed Two views have been held with regard to this question. According to the one view, the fact whether the single band is a prae-oral or a post-oral one depends upon the position in which the anus is about to develop. If the anus develops in such a position that mouth and anus lie on one and the same side of the band, the latter becomes prae-oral ; if, however, the anus develop3 so that the mouth and anus lie upon opposite sides of the band, the band becomes post-oral, If we hold this view we must consider any second band, whether prae- or post-oral, to arise as a new development. The other view premises that the anus always forms so as to leave the primitive ring or “architroch” post-oral, i.e., between mouth and anus. Concurrently with the development of a prostomium this architroch somewhat changes its position and the two lateral portions come to lie longitudinally; these may be supposed to have met in the median dorsal line and to have coalesced so as to leave two rings—the one præ-oral (a “cephalotroch”), the other post-oral (a “ into ”); this latter may atrophy, leaving the single prae-oral ring, or it may become further developed and thrown into more or less elaborate folds. The existing condition of the trochal disk or velum in the Rotifera seems to the writer of this article to bear out the latter view as to the way in which modifications of the velum may have come about. In its simplest condition it forms a single circum-oral ring, as in Microcodon (fig. 1, D). The structures at the sides of the mouth in this form are stated to be bristles, and have therefore nothing to do with the velum (fig. 4, A, p). This simple ring may become thrown into folds, so forming a series of processes standing up around the mouth; this is the condition in Stephanoceros (fig. 4, 5, p). There are, however, but few forms presenting this simple condition; and it must be remembered that the evidence for the assumption here made, that this is a persistent architroch and not a branchiotroch persisting where a cephalotroch has vanished, is not at present conclusive. This band, may, while remaining single and perfectly continuous, become prolonged around a lobe overhanging the mouth—a prostomium. This condition occurs in Philodina. fig. 4: E, F, p); the two sides of the post-oral ring do not meet orsally, but are carried up and are continuous with the row of cilia lining the “wheels.” There is thus one continuous ciliated band, a portion of which runs up in front of the mouth. This condition corresponds to that of the Auricularian larva. The folding of the band has become already somewhat complicated ; a hypothetical intermediate condition is shown in fig. 4, o, D. The next stage in the advancing complexity is that the prostomial por. tion of the band (fig. 4, G, H, p") becomes separated as a Jistinct ring, a cephalotroch; we find such a stage in Lacinularia (fig. 4,
Fig. 4.—Diagram.s of the Trochal Disk. A, Microcodon. B, Stephanoceros; the mouth lies in the centre of a group of tentacles. C, hypothetical intermediate form between Microcodon and Philodina, showing the development of a prostomial portion of the velum. D, dorsal view of the same. E, Philodina. F, dorsal view of the same. G, Lacinularia; the dotted line represents the portion of the velum which has become separated as a special ring—a cephalotrocli. H, dorsal view of the same. I, Melicerta; the dotted line represents the cephalotroch; both this and the branchiotroch have become thrown into folds. J, dorsal view of the same. K,' Brachionus ; there is a large prae-oral lobe with three ciliated regions, shown by the dotted lines c, c, a discontinuous cephalotroch. L, dorsul view of the same. m, mouth; p, ps, velum ; p, architroch; p", portion of the architroch which becomes carried forward to line the prostomial region, but does not become separated ; c, cephalotroch. (Original.)
the oral cavity; (2) tha pharynx; (3) the oesophagus; (4) the stomach; (5) the intestine, which terminates in an amus. anus is absent in one group. The pharynx contains the mastaz with its teeth; these are calcareous structures, and are known as the trophi.
In a typical mastax (8, 9) (Brachiomus, fig. 5, A) there are a median anvil or incus and two hammer-like Portions, onallei. The incus consists of two rami (e) resting upon a central }. (f); each malleus consists of a handle or manubrium (c) and a head or uncus (d), which often }. a combike structure. Fig. à shows some of the most important Fla.;_Trophi : A. Brachionus : modifications which o:*"...i. ;"D. É. % the apparatus may fulcrum, and e, e, rami, forming the incus; c, manubrium, exhibit. The parts and d, uncus, forming the malleus. (After Hudson.) may become very slender, as in Diglena forcipata (fig. 5, B); the mallei may be absent, as in Asplanchna (fig. 5, c), the rami being highly developed into curved forceps and movable one on the other; or, the manubria being absent, and the fulcrum rudimentary, the rami may become massive and subquadratic, as in Philodina (fig. 5, D). All the true Rotifers possess a mastax. Ehrenberg's group of the Agomphia consisted of a heterogeneous collection of forms, —Ichthydium and Chaotonotus being Gastrotricha, and Cyphonautes a Polyzoan larva, while Enteroplea is probably a male Rotifer, and, like the other males, in a reduced condition. There is no reason for considexing this mastaxas the homologue of cither the gastric mill of Crustaceans on the one hand or the teeth in the Chaetopods' pharynx on the other; it is merely homoplastic with these structures, but has attained a specialized degree of development. Both the pharynx and the oesophagus which follows it are lined with chitin. o: oesophagus varies in length and in some genera is absent (Philodimadao), the stomach following immediately upon the pharynx. The stomach is generally large; its wall consists of a layer of very large ciliated cells, which often contain fat globules and yellowishgreen or brown partieks, and outside these a connective tissue membrane; muscular fibrilla have also been described. Very constantly a pair of glands open into the stomach, and probably represent the hepato-pancreatic glands of other Invertebrates. ollowing upon the stomach there is a longer or shorter intestine, which ends in the cloaca. The intestine is lined by ciliated cells. In forms living in an urceolus the intestine turns round and runs forward, the cloaca being placed so as to debouch over the margin of the urceolus. The cloaca is often very large ; the nephridia and oviducts may open into it, and the eggs lodge there on their way outwards; they are thrown out, as are the faecal masses, by an eversion of the cloaca. Asplanchna, Notommata sieboldii, and certain species of Ascomorpha are said to be devoid of intestine or anus, excrementitious matters being ejected through the mouth (11). Nephridia.-The coelom contains a fluid in which very minute corpuscles have been detected. There is no trace of a true vascular system. The nephridia (fig. 2, B, n) present a very interesting stage of development. They consist of a pair of tubules with an intracellular lumen running up the sides of the body, at times merely sinuous, at others considerably convoluted. From these are given off at irregular intervals short lateral branches, each of which terminates in a flame-cell precisely similar in structure to the flame-cells found in Planarians, Trematodes, and Cestodes; here as there the question whether they are open to the coelom, or not must remain at present undecided. At the base these tubes open either into a permanent bladder which communicates with the cloaca or into a structure presenting apparently no advance in its development upon the contractile vacuole of a ciliate Infusorian. Nervous System and Sense-Organs.—Warious structures have been spoken of as nervous which are now acknowledged to have been erroneously so described (18). There is a supra-oesophageal ganglion which often attains considerable dimensions, and presents a lobed appearance (fig. 2, A and B, g). Connected with this are the eye-spots, which are seldom absent. Where these are most highly developed a lens-like structure is present, produced by a thickening of the cuticle. In the genus Rotiser and other forms these are F. upon the protrusible portion of the head, and so appear to ave different positions at different moments. The number of eyespots varies from one to twelve or more. They are usually red, red; dish-brown, violet, or black in colour. Other structures are found which doubtless act as sense-organs. The calcar above-mentioned generally bears at its extremity stiff hairs which have been demonstrated to be in connexion with a nerve fibril. On the ventral surface of the body just below the mouth a somewhat similar structure is often developed—the chin. There are besides at times special organs, like the two lateral organs in Microcodon (fig. 1, D, s), which no doubt in common with the calcar and chin have a tactile function. Reproductive Organs and Development.—The Rotifera were formerly considered to be hermaphrodite, but, while the ovary was always clear and distinct, there was always some difficulty about the testis, and various structures were put forward as representing that organ. One by one, however, small organisms have been discovered and described as the males of certain species of Rotifers, until at the present time degenerated males are known to occur in all the families except that of the Philodinada. The male Rotifers are provided with a single circlet of cilia (a peritroch), a nerve ganglion, eye-spots, muscles, and nephridial tubules all in a somewhat reduced condition, but there is usually no trace of mouth or stomach, the main portion of the body being occupied by the testicular sac. There is an aperture corresponding with the cloaca of the female, where the testis opens into #. base of an eversible penis. The males of Floscularia are shown in fig. 1. The male of Pedalion mira possesses rudimentary appendages. The ovary is usually a large gland lying beside the stomach connected with a short oviduct which opens into the cloaca. The ova often present a reddish hue (Philodina roscola, Brachionus rubens), due doubtless, like the red colour of many Crustacean ova, to the P. of tetronerythrin. Up to the present our embryological knowledge of the group is very incomplete. Many Rotifers are known to lay winter and summer eggs of different character. The winter eggs are provided with a thickshell and probably require fertilization. Two or three of them are often carried about attached to the parent (Brachiomus, Motommata), but they are usually laid and fall into the mud, there to remain till the following spring. The summer eggs are of two kinds, the so-called male and female ova, both of which are stated to develop partlıcnogenetically. They may be carried about in
large numbers in the cloaca or oviduct or attached to the body of the parent. The female ova give rise to female and the male cya to male individuals. Male individuals are only formed in the autumn in time to fertilize the winter ova.
Habitat and Mode of Life.—The Rotifera are distributed all over the earth's surface, inhabiting both fresh and salt water. The greater number of species inhabit fresh water, occurring in pools, ditches, and streams." A few species will appear in countless numbers in infusions of leaves, &c., but their appearance is generally delayed until the putrefaction is nearly over. Species of Rotifer and Philodina appear in this way. A few marine forms only have been described—Brachionus mülleri, B. heptatonus, Synchaeta baltica, and others. A few forms are parasitic. Albertia lives in the intestine of the earthworm ; a form has been described as occurring in the body-cavity of Synapta; a small form was also observed to constantly occur in the velar and radial canals of the freshwater jelly-fish, Limnocodium. Notommata parasitica leads a parasitic existence within the hollow spheres of Volvor globator, sufficient oxygen being given off by the Volvox for its respiration. Many Rotifers exhibit an extraordinary power of resisting drought. Various observers have dried certain species upon the slide, kept them dry for a certain length of time, and then watched them come to life very shortly after the addition of a drop of water. The animal draws itself to: gether, so that the cuticle completely protects all the softer parts and prevents the animal itself from being thoroughly dried. This process is not without parallel in higher groups; e.g., many land snails will draw themselves far into the shell, and secrete a complete operculum, and can remain in this condition for an almost indefinite amount of time. The eggs are also able to withstand drying, and are probably blown about from place to place. The Rotifera can bear great variations cf temperature without injury. Since their removal from among the Protozoa various attempts have been made to associate the Rotifera with one or other large phylum of the animal kingdom. Huxley, insisting upon the importance of the trochal disk, put forward the view that they were “permanent Echino. derm larvae,” and formed the connecting link between the Nemertidae and the Nematoid worms. Ray Lankester proposed to associate them with the Chaetopoda and Arthropoda in a group Appendiculata, the peculiarities in the structure of Pedalion forming the chief reason for such a classification. There is, however, no proof that we thus express any genetic relationship. The well-developed coelom, absence of metameric segmentation, persistence of the trochal disk in varying stages of development, and the structure of the nephridia are all characters which point to the Rotifera as very near representatives of the common ancestors of at any rate the Mollusca, Arthropoda, and Chaetopoda. But the high development of the mastax, the specialized character of the lorica in many forms, the movable spines of Polyarthra, the limbs of Pedalion, and the lateral appendages of Asplanchna, the existence of a diminutive male, the formation of two varieties of ova, all point to a specialization in the direction of one or other of the above mentioned groups. Such specialization is at most a slight one, and does not justify the definite association of the Rotifera in a single phylum with any of them. Classification.—The following classification has been recently put forward by Dr C. T. Hudson (19).
CLASS ROTIFERA. Order I.-Rhizota. Fixed forms; foot attached, transversely wrinkled, non-retractile. truncate. Fam. 1. FLOsculariaDAE. Floscularia, Slephanoceros. Fam. 2. MELIceRTADAE. . Melicerta, Cephalosiphon, Megalotrocha, Limnias, ..fcistes, Lacinularia, Comochilus.
larva while possessing undoubtedly Rotiferal characters. Mecznikow has described a remarkable form, Apsilus lentiformis o 6, D, E, and F), the adult female of which is entirely devoid of cilia but possesses a sort of retractile hood; the young female and the males are not thus modified. Claparéde discovered fixed to the bodies of small Oligochetes a curious non-ciliated form, Balatro calvus (fig. 6, A), which has a worm-like very contractile body and a welldeveloped mastax. As mentioned above, the ciliation is reduced to a minimum in the cuzious worm-like form Lindia (fig. 6, c). Seison nebalia (fig. 6, R), living on the surface of Nebalie, which was described originally by Grube, is the same form as the Saccobdella nebaliae, which was supposed by Wan, Beneden and Hesse to be a leech. . It has been shown by Claus to be merely an aberrant Rotifer. Of the curious * forms Icthydium, Chaetonotus, Turbanella, Dasyditis, Cephalidium, Chatura, and Hemidasys, which Mecznikow and Claparéde included under the name Gastrotricha, no further account can be given here. They are possibly allied to the Iotifera but are devoid of mastax and trochal disk. The following are some of the more important memoirs &c., on the Rotifera. o Leeuwenhoek, Phil. Trans., 1701–1704. (2) Ehrenberg, Die housionshierchen ass vollkommene Organismen, 1838. (3) M. F. Dujardin, Hist. Nat, des Zoophytes: Infusoires, 1841. % W. C. Williamson, “On Melicerta ringons," Quart. Jour. Micr. Sci., 1853. (6) Ph. H. Gosse, “On Melicerta ringens,” Quart. Jour. Micr. Sci., 1858. (6) T. H. Huxley, “On Lacinularia socialis," Trans, Micr. Soc., 1853. ) Fr. Leydig, “Ueber den Bau und die systematische Stellung der Rüderthlere," eit, f w. Zool., vi., 1854. (8) Ph.H. Gosse, Phil. Trans., 1866, (9) F. Cohn, Zeit. f. to. Zool, vii., ix., and xil. (10) Ph. H. Gosse, Phil. Trans., 1858. (11) Pritchard, Infusoria, 1861. (12, 13, 14) C. T. Hudson, “On Pedalion,” Quart. Jour. Micr. &ci., 1872, and Monthly Micr. Jour., 1871 and 1872. (15), E. Itay Lankester, “On Pedalion,” Quart. Jour, Micr. Sci., 1872. (16) El. Mecznikow, "On Apsilus lenti
ROTROU, JEAN DE (1609–1650), the greatest tragic poet of France before Corneille, was born on August 21, 1609 at Dreux in Normandy, and died of the plague at the same place on the 28th June 1650. His family was of small means but of, not inconsiderable station, and seems to have had a kind of hereditary connexion with the magistracy of the town of Dreux. He himself was “lieutenant particulier et civil,” a post not easy to translate, but apparently possessing some affinity to. a Scotch sheriffship substitute. Rotrou, however, went very early to Paris, and, though three years younger than Corneille, with whom he was intimately acquainted, began play-writing before him. With few exceptions the only events recorded of his life are the successive appearances of his plays and his enrolment in the band of five poets who had the not very honourable or congenial duty of turning Richelieu’s dramatic ideas into shape. Rotrou's own first piece, L’Hypocondriaque, appeared when he was only seventeen. His second, La Bague de l'Oubli, an adaptation in part from Lope de Vega, was much better, much more suggestive, and much more characteristic... It is the first of several plays in which Rotrou, following or striking out for himself a way which did not lead to much for the time but which was again entered at the Romantic revival, endeavoured to naturalize in France the romantic comedy which had flourished in Spain and England instead of the classical tragedy of Seneca and the classical comedy of Terence. Corneille, as is known to readers of his early work, had considerable leanings in the same direction, and yielded but slowly and unwillingly to the pressure of critical opinion and the public taste. Rotrou's brilliant but hasty and unequal work showed throughout marks of a stronger adhesion to the Spanish (it is needless to say that neither writer is likely to have known the English) model. Cleagénor et Doristée, Diane, Les Occasions Perdues, L'Heureuse Constance, pieces which succeeded each other very rapidly, were all in the Spanish style. Then the author changed his school, and, in 1632, imitated very closely the Menschmi of Plautus and the Hercules (Eteus of Seneca. A crowd of comedies and tragi-comedies followed, and by the time he was twenty-eight (when documents exist showing the sale of two batches of them to the bookseller Quinet for the sum of 220 livres tournois) Rotrou had written nearly a score of plays. He was married in 1640, and had three children, a son and two daughters (none of whom, however, continued the name), and it seems that he went to live at Dreux, . Previously, vague and anecdotic tradition describes him as having led rather a wild life in Paris, and especially as having been much addicted to gambling. Among his pieces written before his marriage were a translation of the Amphitryon under the title of Les Deuw Sosies, which was not useless to Molière, Antigone, which was not useless to Racine, and Laure Persecutée (in the opposite style to these classical pieces), which has much merit. These were followed by others until, in 1646 and 1647, Botrou produced his three masterpieces, Saint Genest, a story of Christian martyrdom containing some amusing by-play, one noble speech, and a good deal of dignified action ; Don Bertrand de Cabrère, a comedy of merit; and Wenceslas, which is considered in France his masterpiece, and which in a manner kept the stage till our own times. The subject (in which a father, being constrained to choose between his duty as king and his parental affection, pardons his son for a murder he has committed, but immediately abdicates as feeling himself unworthy to reign) was taken from Francisco de Rojas; the execution
though unequal, is in parts very fine. Rotrou's death and its circumstances are known to many who never read a line of his plays. He was in Paris when the plague broke out at Dreux; the mayor fled, and all was confusion. Rotrou, reversing the conduct of Montaigne in somewhat similar circumstances, at once went to his post, caught the disease, and died in a few hours. Rotrou's great fertility (he has left thirty-five collected plays besides others lost, strayed, or uncollected), and perhaps the uncertainty of dramatic plan shown by his hesitation almost to the last between the classical and the romantic style, have injured his work. He has no thoroughly good play, hardly one thoroughly good act. But his situations are often pathetic and noble, and as a tragic poet properly so called he is at his best almost the equal of Corneille and perhaps the superior of Racine. His single lines and single phrases have a brilliancy and force not to be found in French drania between Corneille and Hugo.
the south bank of the river) into those of Delfshaven, Kralingen, and Hillegersberg. A huge dyke on which stands Hoog Straat or High Street divides the triangular portion into nearly equal parts—the inner and the outer town; and the latter is cut up into a series of peninsulas and islands by the admirable system of harbours to which Rotterdam owes so much of its prosperity. The central part of the river frontage is lined by a broad quay called the Boompjes from the trees with which it is planted. From the apex of the triangle the town is bisected by a great railway viaduct (erected about 1870, and mainly constructed of iron), which is continued across the river to Fijenoord and the south bank by a bridge on a similarly grand scale, the line being the Great Southern Railway which connects Belgium and Holland and crosses the Hollandsch Diep by the Moerdij
the railway bridge the municipality, in 1873, built a roadbridge, and apart from their ordinary function these constructions have proved a sufficient barrier to prevent the ice-blocks of the upper part of the river from descending so as to interfere with the seaward navigation. Tramways, introduced in 1880, are being gradually extended to various suburbs. While some nine or ten Protestant sects, the Roman Catholics, the Old Roman Catholics, and the Jews are all represented in Rotterdam, none of the ecclesiastical buildings are of primary architectural interest. The Groote Kerk or Laurenskerk is a Gothic brick structure of the fifteenth century with a tower 297 feet high ; it has a fine rood screen and an excellent organ, and contains the monuments of Lambert Hendrikszoon, Egbert Meeuweszoon Kortenaar, Witte Corneliszoon de Witt, Johan van Brakel, Johan van Liefde, and other Dutch naval heroes. Among the more conspicuous secular buildings are the Boymans Museum, the town-house (restored in 1823–1827), the exchange (1723), the Delft Gate (1766), the court-house, the post and telegraph office (1875), the corn exchange, the seamen's home (1855), the hospital (1846), and the theatres. The Boymans Museum is mainly a picture gallery, which became the property of the town in 1847. When the building, originally erected in 1662–63 as the assembly house of Schieland, was burned down in 1864, most of the pictures perished, but the museum was restored by 1867, and the collection, steadily recruited, is again rich in the works of Dutch artists. The ground floor also contains the city archives and the city library. The maritime museum, established in 1874 by the Yacht Club, is a remarkable collection of ship models, and the Society of Experimental Philosóphy has a considerable collection of instruments, books, and specimens. At the north-west corner of the town an area of several acres is occupied by the zoological garden, which
dates from 1857. Besides the Erasmus Gymnasium the XXI. — 2