structed the famous bridge over the Ticino at Pavia, and commenced the erection of the Cathedral of Milan. His daughter, Valentina, married Louis, the younger brother of Charles VI. of France, and became the grandmother of Louis XII., who upon this relationship founded his claims to the Milanese. Gian Galeazzo's sons, GIAMMARIA (Giovanni Maria) (1388-1412) and FILIPPO MARIA (1391-1447), reigned in succession; the former, who was cowardly, suspicious, and of a cruelty verging on insanity, was murdered, and the younger brother became sole ruler. The Venetians on the east, the Marquis of Montferrat on the west, and the Pope on the south, were rapidly curtailing his dominions, when, by a happy stroke of policy, he espoused Beatrice di Tenda, the widow of a condottieri leader, and thus obtained the services of a veteran band of soldiers. His fortunate choice of Carmagnola (q.v.) as his general led to the restoration of the former boundary line of his dominions. In 1441 he engaged the services of the celebrated condottiere Francesco Sforza (see SFORZA), to whom he gave his natural daughter Bianca in marriage; and on his death the Visconti family was succeeded by that of Sforza (q.v.) in the lordship of the Milanese. Collateral branches of the Visconti still exist in Lombardy. Consult: Sismondi, Histoire des républiques italiennes (Paris, 1826-33); Symonds, Age of the Despots (London, 1875).

VISCONTI. A family of Italian archæologists and architects. GIOVANNI BATTISTA VISCONTI (1712-84), a native of Sarzana, settled at Rome and succeeded Winckelmann as prefect of antiquities. He was employed by Clement XIV. and Pius VI. to collect works of ancient art for the museum of the Vatican, the Museo PioClementino, as it was called. ENNIO QUIRINO VISCONTI (1751-1818) eldest son of Giovanni, as a youth aided his father in the preparation of the first volume of the engravings of the MuseoPio Clementino. In 1784 he edited alone the second volume of the same series, and in 1787 was appointed conservator of the Capitoline Museum. The series of engravings of the Museo was regularly issued, the seventh and last volume being published in 1807. During the French occupation of Rome Visconti was a member of the Government, but in 1799 was compelled to flee to France and settled in Paris, where he was made curator in the Louvre, and professor of archæology. In 1801 appeared his great work, Iconographie grecque, and this was followed by the Iconographie romaine in 1817. In 1817 he went to London by express desire of the British Government, to appraise the value of the Elgin marbles (q.v.), and as a result of this visit published Mémoire sur les ouvrages de sculpture du Parthénon. He died in Paris, February 7, 1818. PIETRO ERCOLE VISCONTI (1802-80), nephew of Louis Tullius Visconti (q.v.), after study. ing at the Papal archæological academy became in 1836 commissioner of antiquities, director of the collections in the Vatican, and professor at the University of Rome. He left uncompleted his History of the Noble Families of Rome and the Papal States.

VISCONTI, LOUIS TULLIUS JOACHIM (17911853). A distinguished French architect, born in 1791 in Rome, the son of Ennio Quirino Vis

conti. He was brought in his eighth year to Paris, where he studied in the Ecole des Beaux-Arts and in the atélier of Charles Percier. Among his varied works in Paris were the architectural designs of the Molière, Louvois, and Saint Sulpice fountains, plans for a Bibliothèque Royale, and the transformation of the Dome des Invalides into a mausoleum for the remains of Napoleon Bonaparte (completed 1853). To him is also due the masterly design for the union of the Louvre and the Tuilleries, a problem which his master Percier, with Fontaine, had earlier endeavored to solve. This colossal enterprise was begun in 1852 under Napoleon III., and carried out during the following thirty years, chiefly under Visconti's associate, Hector Lefuel, who succeeded him on his death in December, 1853. While the exterior detail of the new wings is largely Lefuel's, the general disposition of the plan was Visconti's.

VISCONTI-VENOSTA, vâ-nôs'tå, EMILIO MARCHESE (1829-). An Italian statesman, born in Milan. After his father's death, in 1846, he began to take a prominent part as a journalist in Liberal politics. He became an ardent follower of Mazzini, whom he left in 1853 to join Cavour, and in 1859, after a narrow escape from arrest by the Austrian authorities, he was named royal commissary to Garibaldi. In 1860 he was appointed adviser to the dictator Farini in Parma and Modena, in the interest of annexation to Sardinia, was elected to the Chamber of Deputies in the same year, and became Minister of Foreign Affairs in the Minghetti Cabinet in 1863, but resigned in 1864 because of popular disapproval of the convention of September, which he had concluded with France. In 1866 he became Ambassador to Constantinople, but was recalled to take charge again of the Foreign Office and conclude peace with Austria, after which he was retired. Again in 1869 he was made Foreign Secretary in Lanza's Cabinet and held the portfolio until the fall of the Right from power in 1876, when he retired, having passed the 'Guarantigie pontificie.' Visconti-Venosta became Senator in 1886, and in 1896 again received the portfolio of Foreign Affairs under Rudini, but was forced out by revolts in Milan and by general opposition to his conservative policy, in May, 1898. In 18991900 he was Foreign Minister in the Pelloux Cabinet, and in 1900-01 held the same post under Saracco. The most striking item in ViscontiVenosta's foreign policy was his eager friendship for France.

VISCOSITY (from Lat. viscosus, viscous, sticky, from viscum, viscus, bird-lime, Gk. ¿bs, ixos, mistletoe). When currents are produced in fluids, forces are observed which retard the relative motion of the parts. These forces of friction are said to be due to 'viscosity;' and the greater the friction, the more viscous the fluid.

VISCOUNT (OF. visconte, viconte, Fr. vicomte, from ML. vicecomes, viscount, from Lat. vice, in place of comes, companion, count). In English history, originally the officer who acted as deputy to the earl, the earl being the King's immediate officer within his county. The hereditary title of viscount is a degree of nobility unconnected with office. It was first granted in England to John Beaumont, created a peer by the title of Viscount Beaumont in 1440. A viscount's

coronet consists of a chased circlet of gold, round which are ranged an indefinite number of pearls, nine of them being most generally shown, smaller than those of a baron's coronet, and in contact with each other. The mantle is scarlet, and has two doublings and a half of ermine. A viscount is styled 'right honorable;' his wife is a viscountess; his eldest son has no courtesy title of peerage, but all his sons and daughters are styled 'honorable.' The title has a not dissimilar history in France, Italy, and Spain.

VISCUM. See MISTLETOE.

VISH'NU (Skt. visņu; of uncertain etymology). The second god of the Hindu triad (see TRIMURTI), and regarded as the supreme deity by his worshipers, who are called Vaishnavas (q.v.).

In the Rig-Veda Vishnu is the 'wide-stepping god who 'goes swiftly' and 'establishes the vault of heaven' and 'measures out the extreme spaces of earth,' while his 'dear path' is the heaven of pious men, or along the highest heavens. The deity thus described is apparently the sun, though some scholars prefer to regard the Vedic Vishnu as a giant of earth, his famous 'three strides' through the universe being interpreted as across the ground rather than through the sky. In the second period of Hindu thought, however, the union of the sun-god and Vishnu is complete, and at the same time Vishnu becomes much more important and more generally recognized as one of the supreme gods, appearing even as the supreme deity. The next phase of his character is that of a supreme All-god. About the time of the Christian Era this pantheistic Vishnu, who represents on the one hand the esoteric speculations of philosophy, and on the other the figure of a popular godling, entered into so close rivalry with the orthodox supreme god, Brahma, and with the sectarian god, Siva, that to reconcile the conflicting claims of each party the three were proclaimed to be forms of the same one supreme god. When this step was taken, Vishnu as a distinct personality disappeared, being merged with Brahma and Siva, and thenceforward he represented only a personal condition of the one All-god. While Brahma became more and more a deity of philosophers and Siva remained an object of fear, Vishnu became especially the god of the easy-going, life-loving middle classes, both in the northern and southern divisions of India, and ended his divine career by absorbing most of the local cults of the Hindu and barbarian natives. He was supposed to have descended from his heaven and become incorporate in various guises. These are the famous avatars of Vishnu. (See AVATAR.) In them the Vishnu appeared only in part; for being the All-god, the individual form was only a portion of the whole. This theory of avatars did more than anything else to make Vishnu a popular god; for, according to it, any local god might be a form of the All-god. This provided a means of bringing into the Brahmanic fold the worshipers of the most diverse divinities.

The oldest legends of the avatars have to do with mythical animals; then follow avatars in half human form, and finally come the great human avatars. Among these the oldest of all is the fish-avatar. At first, before Vishnu was recognized as All-god, we find the legend of a

deluge, and the story of a monster fish, which preserved from death in the flood the ancestor of all mankind. The orthodox Brahmanic theologians assert that the saving fish was an incarnation of the god Brahma. It is not till much later that Vishnu is substituted for the earlier god. In no other instance is the historical genesis of the avatar so plainly preserved as in this, wherein a popular tale is transferred from one divinity to another.

The numerous avatars of Vishnu are given at first as ten, then as twenty, then again as twentytwo, and at last they become innumerable. First comes the fish-avatar already referred to; then the tortoise and boar avatars. These comprise the first group, in which possibly a totemic deity has been identified with Vishnu. The next group comprises the half-human man-lion form of Vishnu and the dwarf form, in which the deity is half beast and half god respectively. The tortoise and boar forms, like that of the fish form, are assumed in order to save earth itself from disaster. Both tortoise and boar raise the sinking land, so that these are also merely forms of a deluge-myth. In the dwarf avatar Vishnu tricks an evil demon, who possesses earth, by soliciting as much earth as the petitioner can cover with three strides. On this request being granted, the god renounces his dwarf form and with his ancient three strides covers the whole of earth. The last group of avatars comprises those of the two Ramas and of Krishna, together with the final claim or admission that Buddha was an avatar of Vishnu and the prediction that there is to be another avatar, that of the Saint Kalki. In this last group of avatars, beginning with the older Rama, the evil counteracted by Vishnu in human form is moral, not, as in the earlier legends, merely physical evil.

The most important of these avatars are those in human form. As Rama or as Krishna, the god Vishnu is worshiped by millions of Hindus, whereas in other forms he has only a restricted circle of worshipers, generally limited to a local cult. Especially is this true of the speculative avatars, such as Buddha in the group of ten, or as Kapila (the reputed inventor of the Sankhya philosophy) in the later group of twentytwo. In regard to these forms it may be said that the god is not really worshiped under them, but they are postulated merely on the general theory that the greatest men of the race, unless positively antagonistic to the Vishnu cult, must have been incarnations of the deity.

All these legends have resulted in swelling enormously the sectarian literature which clusters about Vishnu, and almost every legend has received its special gospel in the shape of a Purana (q.v.) or two.

When freed from all avatars, Vishnu as the supreme god, or as a member of the Trimurti and not as a mere name for the pantheistic All-god, is conceived as having a special heaven, called Vaikuntha. His wife is Lakshmi (q.v.), or the goddess of good fortune, and he is represented as dark in color, with four hands, his emblems being a disk (due to his solar attributes), a conchshell or trumpet (such as he bore in battle), a lotus (from the heart of which Brahma is supposed to have been born), and a mace or sword. Other representations picture his avatars as a beautiful youth, to typify Krishna or Rama. The

epic gives him a thousand names, most of which are epithets describing him as all-glorious, allpowerful, the savior, the preserver, or the very great one.

There is, however, another aspect of Vishnu, which may be called his philosophical form. In this form Vishnu becomes a mere name (interchangeable with Brahma or Siva) of the All-god as philosophically conceived. As such Vishnu is not a demiurge, which in all sectarian forms is his real position, but a being without parts or passions, having no attributes save those of being and knowledge. He is the name of the worldspirit out of which comes and into which returns all the transient group of phenomena which have no real existence and are due merely to ignorance on the part of those who live conditioned by these phenomena. This is the Vishnu of the Vedanta (q.v.), differing both from the Krishna-Vishnu of the sectary and from the Vishnu of the Trimurti, or triad of the co-equal supreme gods. Since Vishnu may be and is worshiped under any of these conceptions, he comes nearest to the allsufficing notion of God, and his cult appeals alike to the grosser intellect of the sectary and to the most refined thought of the logician. In all of these phases may be seen a survival of the primi

tive sun-god. On the one hand the identification of the sun's place with the place of departed spirits led to a mystic conception of the god, whose attribute of light was further identified with that of goodness. On the other hand, the fructifying power of the sun led to the apotheosis of the gen erative power in man as in nature, and it is this function which is the chief element in Krishna worship, Krishna being renowned as the amorous shepherd, whose thousand wives or mistresses are his principal delight.

In sharp contrast to Siva, Vishnu is at all times a kindly god, and his cult is indicative of this fact. To him are offered no bloody sacrifices. He desires only the sacrifice of fruit and vegetables, milk and honey. The esoteric rites in honor of his human incarnations are also bloodless, though licentious in their debased form. On the whole he is a deity of light and joy. Gay banners and brilliant illuminations are seen at his feasts, and his many temples are crowned with flowers, not with the skulls of victims. Under the form of Juggernaut, or Jagannath (q.v.), the savior of the world, he has been credited with taking pleasure in human sacrifice, but this is a gross error.

The sacred scriptures of Vishnu are of two sorts. The first are the few early texts which express a belief in Vishnu as the supreme god. Such expressions of belief are always incidental in the first instance, and they would not be of influence if it were not for the later evolution of Vishnu into the All-god. The earliest Upanishads (q.v.) and the still earlier Brahmanas (q.v.) do not recognize Vishnu as in any way a supreme deity. The second class of scriptures includes the Bhagavadgita (q.v.), in which for the first time Krishna appears as Vishnu incarnate on earth, and the Visnu Purānas, of which there are several, the oldest being called simply Viṣņu Purāṇa, and the most popular being the Bhāgavata Purāṇa. These, together with a supplement to the Mahabharata called the Harivansa (q.v.) or genealogy of Krishna (as Vishnu), in which are told marvelous tales of Krishna's youthful

exploits, are the classic texts in honor of the god, though each of the Vishnu sects (see VAISHNAVAS) has scriptures of its own. Consult: Muir, Original Sanskrit Texts (London, 185863); Hopkins, Religions of India (Boston 1895); Macdonell, Vedic Mythology (Strassburg, 1897), and see VISHNU in Plate of HINDU DEITIES, in the article INDIA.

VISIBLE SPEECH. A scientific form of universal alphabetics, devised by A. Melville Bell (q.v.) in 1848, which is equally adapted to every nation and spoken language. There is not a phonetic element in any language that cannot be reduced to its established standard of articulate correctness and accurately represented. Hence, visible speech, correctly written and read, presents and acts respectively the same linguistic Sounds in every country. Human speech, however,

consists of certain movements of the throat, tongue, and lips, associated in different countries with different sets of letters, so that one may know the letters perfectly in connection with a certain language, and yet be unable to protively obviated by visible speech, as it consists in nounce them in some other language. This is effecments of the organs of speech, and inasmuch as a form of writing which depicts the actual move

these organs are alike in all men, and the effect of every action is the same in all mouths, the symbols used in graphically giving their requisite of pronunciation in every language, regardless movements result in a strictly uniform standard of linguistic differences and local peculiarities. For the characters employed in the system, see DEAF MUTE.

VISION, or SIGHT. That sense which gives us knowledge of our surroundings through the medium of the eye and includes impressions of form, of colorless light (black, white, and gray), and of color. The function of the eye is the reception of stimuli imparted by means of vibrations of the surrounding ethereal medium (luminiferous ether), and the transference of corresponding stimuli to the optic nerve; the latter serves to transmit the resulting nerveexcitations to the occipital lobes of the brain. where they are concomitant with sensations of sight.

THE CONNECTION OF THE EYEBALL WITH THE BRAIN. (For a description of the eyeball, see EYE. ) The eyeball is connected with the brain by a slender cord of nerve filaments, the optic nerve, destruction of which causes blindness. This nerve passes through a small opening in the apex of the orbit and thus reaches the interior of the skull; after passing along the base of the brain a short distance, the optic nerves of the two sides unite, a part of the fibres decussating and passing to the opposite side, a portion continuing upon the same side as the eye from which they arise. Penetrating the substance of the brain, the fibres of the optic nerve finally terminate in nerve cells of the gray covering at a region situated in the median and posterior aspect of the brain, known as the visual cortical area.

THE FORMATION OF IMAGES. Diffuse light gives rise merely to the impression of luminosity. In order to see objects distinctly, light must be collected so as to produce a sharply defined image upon the retina; this process constitutes focus

ing. Rays from different points of the object must be focused at corresponding points on the retina, and every radiant point of the object must have a corresponding focal point in the image (Fig. 1). If, for instance, the usually transparent

X

FIG. 1. Illustrating the formation of an image of an external object upon the retina.

cornea be rendered opaque by some disease, the person will still perceive light, but will be unable to recognize objects.

The eye serves as an optical instrument which receives and focuses upon the retina rays of light from an object; it is often likened to the photographic camera, an interesting comparison that is founded upon many points of resemblance. Thus, the camera incloses a dark chamber, the walls of which are blackened so as to prevent reflection and the resulting irregular illumination which would interfere with the definition of images; in front, it presents an opening for the admission of rays of light; in this aperture is placed a glass lens or series of lenses designed to refract the rays of light and bring them to a focus upon the sensitive plate placed in the back of the instrument; the latter is capable of being moved forward or backward so that its position will correspond to the focus of the rays.

Compared with the camera, the eye possesses all these parts, arranged, of course, in a much more delicate and wonderful manner. It is a dark chamber, lined with the black pigment of the retina and choroid, presenting an opening in front for the admission of light (the pupil), and provided with a sensitive layer (the retina). The focusing is accomplished by the transparent media of the eyeball (cornea, aqueous humor, lens, and vitreous humor), of which the lens plays the most important part. The marginal rays, which would cause a blurring of the image (spherical aberration) and a chromatic ring (chromatic aberration), and which are cut off in the camera by a series of stops or diaphragms, are excluded in the eye by a colored curtain, the iris. The opening in the iris, the pupil, enlarges or diminishes in size according to various conditions presented. In a bright light and when the eye is focused upon near objects, the pupil contracts; in a dim light and with distant vision, the pupil enlarges. These changes occur unconsciously and automatically, whereas in the camera the adjustment is effected by mechanical means and requires different diaphragms for various changes in the distance of the object and the intensity of illumination.

ACCOMMODATION. The focusing apparatus of the eye is of wonderful construction. When we look at a distant object, the lens is kept flat by the tension of its capsule and its suspensory ligament, and is consequently less refractive; rays proceeding from a distant object being less divergent than from a near source, less power is required to focus such rays upon the retina. When the eye is fixed upon a near object, the rays

coming from the latter being more divergent, greater refractive power is necessary in order to produce a distinct image upon the retina. Under such circumstances, the lens increases its convexity, especially that of its anterior surface, through relaxation of its ligament and capsule, and consequently increases its power. This change in the thickness and power of the lens, adapting the focus of the eye to various distances, is known as accommodation. It is due to the action of the ciliary muscle, which by its contraction relaxes the capsule of the lens, and thus allows the latter to bulge anteriorly. The fact that muscular action is responsible for this increase in the convexity and hence in the refractive power of the lens explains why the continued use of the eye for near vision results in fatigue. We can look at distant objects, such as scenery, for long periods with a feeling of comparative rest; but when reading a book or engaging in other similar use of the eyes, we focus for near objects; and the continued action of the ciliary muscle under such circumstances causes fatigue, which is just as natural as the tired sensation of the legs following long continued action of the muscles of these extremities in walking. Accommodation in the adult has a range from infinite distance to about six inches. After the age of forty-five the human lens becomes less elastic; as a result there is gradual loss of power to adjust the eye for near objects (presbyopia or old sight), which requires for its correction the use of spectacles containing convex lenses.

THE RETINA. This is the portion of the eye sensitive to light waves, and is described under EYE. The particular part thus sensitive is the layer which is called the rods and cones. This layer is composed of great numbers of minute rod-shaped and cone-shaped bodies. Light entering the eye influences the rods and cones in some manner not yet understood, though the changes are supposed to be photochemical in their nature; these changes in the rods and cones, produced by the vibrations of the luminiferous ether, result in stimuli which are transferred to the fibres of the optic nerve. Stimulation of the retina, in whatever way produced, is accompanied by the sensation of light; thus, with pressure on the eyeball there are luminous impressions (phosphenes), and with electrical stimulation, irritation of any sort, or division of the optic nerve there is the sensation of flashes of light.

In the outer portion of the rods, though not in the cones, is a purplish-red matter known as bleaches upon exposure to light and is regenthe visual purple, or the rod-pigment; this erated during darkness or a faint light. It is not essential to vision, since it is absent from a part of the retina identified with most accurate sight: this area consists of cones only. Since the rod-pigment exists, in any appreciable quantity, only when the illumination is faint, and is found abundantly in the retina of the owl and other night-birds, but not at all in the rods of those animals which 'go to bed with the chickens,' it is believed to be the source of the adaptation to a faint light which the eye experiences after being for twenty minutes in a darkened room ('extended' Purkinje phenomenon). It is very probable that the rods themselves con

stitute an apparatus for impressions in black and white only, and are wholly insensitive to color.

THE FIELD OF VISION. The sensitiveness of the retina varies in different parts. The most sensitive portion corresponds to the posterior pole of the eyeball, a region which is called on account of its color the yellow spot or macula lutea, and on account of its special endowment the region of most distinct vision; this area presents in its centre a depression called the fovea. The fovea has no nerve fibres, blood-vessels, or retinal elements excepting cones; even the rods are absent. The macula (and still more markedly the fovea) serves to receive all those luminous sensations which give rise to distinct impressions of vision. When we wish to see anything distinctly, we turn the eyeballs toward the object, so that the image will fall upon this spot. Other parts of the retina are much less sensitive to form and color, but not to variations in brightness.

Vision can, therefore, be divided into (1) central or distinct, when the image of the object falls on the macula, and (2) peripheral, when the image falls on some other part of the retina. The space before the eye within which objects are seen, even though indistinctly, constitutes the visual field; its dimensions for each eye are: Externally or toward the temple, 90°, above 50°, below 70°, and internally or toward the nose, 60°; these represent the limits for white light, the fields for colors being less extensive. Though not adapted for distinct vision or for colorvision, the peripheral field is of the greatest use in giving us knowledge of the existence of objects placed outside of the direct line of vision; without it our surroundings would have the appearance which we get when we look through a tube. Though we see indistinctly with peripheral vision, eccentric portions of the retina are more sensitive to differences of light, irrespective of form and color, than the macula; hence in a very dim light we can often see an object better when it is outside of the line of direct vision, that is, when we are not looking directly at it.

FIG. 2. For use in the experiment to demonstrate the existence of the blind spot in the field of vision. upon a sheet of paper, two or three inches apart (Fig. 2), the left eye is closed and the right eye fixed upon the cross; if now the sheet be moved forward and backward before the exposed eye, the round spot will disappear fror view at a certain distance (about 3% times the distance between the two figures) whenever its image falls upon the blind spot. See BLIND SPOT.

The retina is supplied with blood-vessels which enter the eyeball with the optic nerve and, branching into smaller ramifications, spread out in the inner layer of the retina. Since they occupy a plane in front of that of the sensitive layer (rods and cones), they must cast a visible shadow; we are not usually conscious of these shadows, but we can be made aware of their existence by the following experiment. If, in a dark room, which serves to make the retina sensitive, after a time, to faint illumination, we keep a lighted candle moving upward and downward on one side of the eye, these shadows will become visible as beautiful arborescent lines.

THE OPHTHALMOSCOPE. All details of the inner aspect of the retina become visible when the eye is explored with the ophthalmoscope, an instrument invented by Helmholtz in 1851, the essential part of which is a perforated mirror which serves to reflect light into the interior of the eye.

INTERPRETATION OF RETINAL IMAGES. The stimuli affecting the fibres of the optic nerve whenever the rods and cones of the retina are excited by the vibrations of the luminiferous ether are conveyed to the brain, where they determine changes in the cortical cells. The accompanying impressions are then referred by consciousness to definite positions in external space. Each point in a retinal image is referred to an external point in the line of direction (line through the nodal point of the eye) and consequently to the opposite side of the field of vision; objects seen to the right cast their images upon the left side of the retina, those occupying the left side of the field upon the right side of the retina. Though usually excited by stimuli from without, the retina may also be affected by luminous sensations independent of external causes, or the cerebral centre of sight may be the seat of excitation, producing impressions which are in every case referred to external space, thus giving rise to delusive visual phenomena (hallucinations). See DISTANCE; LOCALITY; MOVEMENT, PERCEP

TION OF.

CORRESPONDING POINTS. Every part of the ret ina has its corresponding point in the field of vision; this is found by projecting a line from the retinal point through the nodal point of the eye, situated near the posterior pole of the lens. As a result of this law, it follows that the retinal image must be reversed as compared to the external object, the upper portion of the field corresponding to the lower part of the retina, and the lower portion of the field to the upper part of the retina. There has been much discussion as to how it is that we see objects right side up when the retinal image is inverted, but the belief that there is here anything to be explained is due to a misconception. We have no consciousness of either the retinal image or the retina, any more than of the crossing of the fibres of the optic nerve in the optic chiasm. Visual sensation follows only upon an excitation of the cortex of the brain, and if we were conscious of any part of the mechanism of seeing, it ought to be of the (chemical) reproduction of the image upon the visual cortical area. To suppose that we know anything about the physiological basis of our sensations, subjectively, is to commit what Professor James has called the psychologist's fallacy-the fallacy of thinking