SULC  . FR.See also:

• ORB

ORB . 'SULC . ORB . From See also:

• CAT
• CAT, CIVET
• CAT, HOUSE

Cat . R.C.S . See also:

• ENGLAND
• ENGLAND, THE CHURCH OF

England . a communication not only between the third and lateral ventricles, but between the two lateral ventricles, so that the cavity of each hemisphere is continuous with that of the other; soon, however, a median See also:

• LONGITUDINAL

longitudinal fissure forms, into which the mesoderm grows to See also:

• FORM (Lat. forma)

form the falx, and so the foramina of See also:

• MUNRO, HUGH ANDREW JOHNSTONE (1819-1885)
• MUNRO, MUNRO
• MUNRO, SIR HECTOR (1726-1805)
• MUNRO, SIR THOMAS (1761-1827)

Munro are constricted into a V-shaped See also:

• CANAL
• CANAL (from Lat. canalis, " channel " and " kennel " being doublets of the word)

canal . In the See also:

• FLOOR (from O. Eng. flor, a word common to many Teutonic languages, cf. Dutch vloer, and Ger. Flur, a field, in the feminine, and a floor, masculine)

floor of the hemispheres the corpora striata are See also:

• DEVELOPED

developed at an See also:

• EARLY
• EARLY, JUBAL ANDERSON (1816-1894)

early date by a multiplication of See also:

• NERVE (Lat. nervus, Gr. vevpov, a bowstring)

nerve cells, and on the See also:

• EXTERNAL

external See also:

• SURFACE

surface a depression, called the Sylvian fossa, marks the position of the future central See also:

• LOBE

lobe, which is after-wards hidden as the lips of the fossa (opercula) gradually See also:

• CLOSE
• CLOSE (from Lat. clausum, shut)
• CLOSE, MAXWELL HENRY (1822-1903)

close in on it to form the Sylvian fissure . The real fissures are See also:

• COMPLETE

complete infoldings of the whole thickness of the vesicular See also:

• WALL (O. Eng. weal, weall, Mid. Eng. wal, wane, adapted from Lat. vallum, rampart; the original O. Eng. word for a wall was wag or tenth)
• WALL, RICHARD (1694-1778)

wall and produce swellings in the cavity . Some of them, like the choroidal on the mesial surface, are developed very early, while the vesicle is little more than See also:

• EPITHELIAL, ENDOTHELIAL

epithelial, and contain between their walls an inpushing of mesoderm to form the choroid plexus . Others, like the hippocampal and calcarine, appear in the second and third months and correspond to invaginations of the See also:

• NERVOUS

nervous See also:

• TISSUE (Fr. tissu, tissue, participle of tisser, Lat. texere, to weave)

tissue, the hippocampus See also:

• MAJOR
• MAJOR (Lat. for " greater ")
• MAJOR (or MAIR), JOHN (1470-1550)

major and See also:

• MINOR
• MINOR (Lat. for smaller, lesser)
• MINOR, ROBERT CRANNELL (1839-1904)

minor .

The See also:

• SULCI

sulci appear later than the fissures and do not affect the See also:

• INTERNAL

internal cavity; they are due to the rapid growth of the cortex in certain areas . The corpus callosum and fornix appear about the third See also:

• MONTH
• MONTH (a common Teutonic word, cf. Ger. Mond, Du. maand, Dan. maaned, &c., and cognate with Lat. mensis, Gr. µi7v, &c., in other branches of the Indo-Germanic family; all ultimately from the root seen in the word for the moon in nearly all those languages

month and their development is somewhat doubtful; they are probably modifications of the lamina terminalis, but they may be secondary adhesions between the adjacent surfaces of the cerebral hemispheres where the cortical See also:

• GREY, CHARLES GREY, 2ND EARL (1764-1845)
• GREY, HENRY GREY, 3RD EARL (1802-1894)
• GREY, LADY JANE (1537-1554)
• GREY, SIR EDWARD
• GREY, SIR GEORGE (1812–1898)

grey See also:

• MATTER

matter has not covered the See also:

• WHITE
• WHITE, ANDREW DICKSON (1832– )
• WHITE, GILBERT (1720–1793)
• WHITE, HENRY KIRKE (1785-1806)
• WHITE, HUGH LAWSON (1773-1840)
• WHITE, JOSEPH BLANCO (1775-1841)
• WHITE, RICHARD GRANT (1822-1885)
• WHITE, ROBERT (1645-1704)
• WHITE, SIR GEORGE STUART (1835– )
• WHITE, SIR THOMAS (1492-1567)
• WHITE, SIR WILLIAM ARTHUR (1824--1891)
• WHITE, SIR WILLIAM HENRY (1845– )
• WHITE, THOMAS (1628-1698)
• WHITE, THOMAS (c. 1550-1624)

white . They begin at their antero-ventral See also:

• PART

part near the genu of the corpus callosum and the anterior pillars of the fornix, and these are the parts which first appear in the See also:

• LOWER

lower mammals . The See also:

• ORIGINAL

original anterior vesicle from which the hemispheres evaginate is composed, as already shown, of an anterior part or telencephalon and a posterior or thalamencephalon; the whole forming the third ventricle in the adult . Here the alar and basal laminae are both found, but the former is the more important; from it the optic thalami are derived, and more posteriorly the geniculate bodies . The anterior wall, of course, is the lamina terminalis, and from it are formed the lamina cinerea, the corpus callosum, fornix and septum lucidum . The roof largely remains epithelial and is invaginated into the ventricle by the mesoderm to form the choroid plexuses of the third ventricle, but at the posterior part it develops the ganglia habenulae and the pineal See also:

• BODY

body, from a structure just in front of which both a See also:

• LENS
• LENS (from Lat. lens, lentil, on account of the similarity of the form of a lens to that of a lentil seed)

lens and retinal elements are derived in the lower forms . This is one See also:

• GREAT

great difference between the development of this See also:

• ORGAN

organ and that of the true eyes; indeed it has been suggested that the pineal is an organ of thermal sense and not the remains of a median See also:

• EYE
• EYE (O. Eng. edge, Ger. Auge; derived from an Indo-European root also seen in Lat. oc-ulus, the organ of vision (q.v.)

eye at all . The floor of the third ventricle is developed from the basal laminae, which here are not very important and from which the tuber cinereum and, until the See also:

• FOURTH

fourth month, single corpus mammillare are developed, The infundibulum or stalk of the posterior part of the pituitary body at first grows down in front of the tuber cinereum and, according to Gaskel's theory, represents an ancestral mouth to which the ventricles of the See also:

• BRAIN (A.S. braegen)

brain and the central canal of the See also:

• CORD (derived through the Fr. corde, from the Lat. chorda, Gr. xop(5rt, the string of a musical instrument)

cord acted as the See also:

• STOMACH (Gr. vrbsaxos from arbga, a mouth)

stomach and See also:

• INTESTINE (Lat. intestinus, internal, usually in neuter plural intestina. from intus, within)

intestine (Quart . Journ. of Mic . Sci . 31, p .

379; and Journ. of Phys. v. to, p . 153) . The See also:

• REASON (Lat. ratio, through French raison)

reason why the basal lamina is here small is because it contains the nuclei of no See also:

• CRANIAL

cranial nerves . The anterior and posterior commissures appear before the See also:

• MIDDLE

middle ,and the middle before the corpus callosum, as they do in phylogeny . In connexion with the thalamencephalon, though not really belonging to it, may be mentioned the anterior lobes of the pituitary body; these begin as an upward diverticulum from the posterior wall of the See also:

• PRIMITIVE

primitive pharynx or stomatodaeum about the fourth See also:

• WEEK (from A.S. wicu, Germanic *wikon, probably=change, turn)

week . This See also:

• TOUCH (derived through Fr. toucher from a common Teutonic and Indo-Germanic root, cf. " tug," " tuck," O. H. Ger. zucchen, to twitch or draw)

touch of Rathke, as it is called, becomes nipped off by the developing See also:

• BASE

base of the See also:

• SKULL

skull, and its bifid See also:

• BLIND, MATHILDE (1841—1896)

blind end meets and becomes applied to the posterior part of the body, which comes down from the brain . In the mesencephalon the alar laminae form the corpora quadrigemina; these at first are bigeminal and hollow as they are in the lower vertebrates . The basal laminae thicken to form the crura cerebri . In the rhombencephalon the See also:

• DIVISION (from Lat. dividere, to break up into parts, separate)

division into basal and alar laminae is better marked than in any other part; there is a definite groove inside the fourth ventricle, which remains in the adult as the See also:

• SUPERIOR

superior and inferior fovea and which marks the separation between the two laminae . In the basal laminae are found the deep origins of most of the motor cranial nerves, while those of the sensory are situated in the alar laminae . The roof of the fourth ventricle widens out very much and remains largely epithelial as the superior and inferior medullary vela . The cerebellum develops in the anterior part of the roof of the rhombencephalon as two lateral rudiments which unite in the See also:

• MID

mid See also:

• LINE

line and so form a transverse See also:

• BAR
• BAR (0. Fr. barre, Late Lat. barra, origin unknown)
• BAR, CONFEDERATION OF
• BAR, FRANCOIS DE (1538-1606)
• BAR, THE

bar similar to that seen in the adult See also:

• LAMPREY

lamprey; at the end of the second month the flocculus and paraflocculus become marked, and later on a See also:

• SERIES (a Latin word from serere, to join)

series of transverse fissures occur dividing the various lobes .

Of the cerebellar peduncles the inferior develops first (third month), then the middle forming the pons (fourth month), and lastly the superior (fifth month) (Elliot See also:

• SMITH
• SMITH, ADAM (1723–1790)
• SMITH, ALEXANDER (183o-1867)
• SMITH, ANDREW JACKSON (1815-1897)
• SMITH, CHARLES EMORY (1842–1908)
• SMITH, CHARLES FERGUSON (1807–1862)
• SMITH, CHARLOTTE (1749-1806)
• SMITH, COLVIN (1795—1875)
• SMITH, EDMUND KIRBY (1824-1893)
• SMITH, G
• SMITH, GEORGE (1789-1846)
• SMITH, GEORGE (184o-1876)
• SMITH, GEORGE ADAM (1856- )
• SMITH, GERRIT (1797–1874)
• SMITH, GOLDWIN (1823-191o)
• SMITH, HENRY BOYNTON (1815-1877)
• SMITH, HENRY JOHN STEPHEN (1826-1883)
• SMITH, HENRY PRESERVED (1847– )
• SMITH, JAMES (1775–1839)
• SMITH, JOHN (1579-1631)
• SMITH, JOHN RAPHAEL (1752–1812)
• SMITH, JOSEPH, JR
• SMITH, MORGAN LEWIS (1822–1874)
• SMITH, RICHARD BAIRD (1818-1861)
• SMITH, ROBERT (1689-1768)
• SMITH, SIR HENRY GEORGE WAKELYN
• SMITH, SIR THOMAS (1513-1577)
• SMITH, SIR WILLIAM (1813-1893)
• SMITH, SIR WILLIAM SIDNEY (1764-1840)
• SMITH, SYDNEY (1771-1845)
• SMITH, THOMAS SOUTHWOOD (1788-1861)
• SMITH, WILLIAM (1769-1839)
• SMITH, WILLIAM (c. 1730-1819)
• SMITH, WILLIAM (fl. 1596)
• SMITH, WILLIAM FARRAR (1824—1903)
• SMITH, WILLIAM HENRY (1808—1872)
• SMITH, WILLIAM HENRY (1825—1891)
• SMITH, WILLIAM ROBERTSON (1846-'894)

Smith, See also:

• REVIEW (Fr. revue, from revoir, to see again, Lat. re and videre)

Review of Neurology and Psychiatry, See also:

• OCTOBER

October 1903 ; W . Kuithan, " See also:

• DIE
• DIE (Fr. de, from Lat. datum, given)

Die Entwicklung See also:

• DES

des Kleinhirns bei Saugetieren," Munchener Med . Abhandl., 1895; B . See also:

• STROUD

Stroud, " Mammalian cerebellum," Journ. of Comp . Neurology, 1895) . Much of our knowledge of the tracts of See also:

• FIBRES
• FIBRES (or FIBERS, in American spelling; from Lat. fibra, apparently connected either with filum, thread, or findere, to split)

fibres in the brain is due to the fact that they acquire their white sheaths at different stages of development, some See also:

• LONG, GEORGE (1800-1879)
• LONG, JOHN DAVIS (1838– )

long after See also:

• BIRTH (a word common in various forms to Teutonic languages from the root of the verb " to bear ")

birth . For further details and references see See also:

• QUAIN, SIR RICHARD, BART

Quain's Anat. vol. i . (1908) ; See also:

• MINOT, LAURENCE (fl. 1333—1352)

Minot's Human See also:

• EMBRYOLOGY

Embryology (New See also:

• YORK
• YORK (HOUSE OF)
• YORK, EDMUND OF LANGLEY, DUKE OF (1341-1402)
• YORK, EDWARD
• YORK, FREDERICK AUGUSTUS, DUKE OF (1763-1827)
• YORK, RICHARD, DUKE

York) ; W . His, Anat. menschlicher Embryonen (See also:

• LEIPZIG

Leipzig, 1881) ; See also:

• MARSHALL
• MARSHALL, ALFRED (1842– )
• MARSHALL, JOHN (1755–1835)
• MARSHALL, JOHN (1818-1891)
• MARSHALL, STEPHEN (c. 1594-1655)

Marshall's Vertebrate Embryology; See also:

• KOLLIKER, RUDOLPH ALBERT VON (1817-1905)

Kolliker, Grundriss der Entwickelungsgeschichte (Leipzig, 188o) ; A . See also:

• KEITH
• KEITH, FRANCIS EDWARD JAMES (1696-1758)
• KEITH, GEORGE (c. 1639-1716)
• KEITH, GEORGE KEITH ELPHINSTONE, VISCOUNT (1746-1823)

Keith, Human Embryology and See also:

• MORPHOLOGY, (Gr. yopdsil, form)

Morphology (See also:

• LONDON

London, 19o4); 0 . Hertwig, Handbuch der vergleichenden and experimentellen Entwickelungslehre der Wirbeltiere, Bd . 2, part 3 (See also:

• JENA

Jena, 1902—1906); Development of the Human Body, J .

P . McMurrich (1906) . (F . G . P.) 2 . See also:

• PHYSIOLOGY (from Gr. 4 i s, nature, and koyos, discourse)

PHYSIOLOGY The nervous See also:

• SYSTEM

system has as its See also:

• FUNCTION

function the co-ordinating of the activities of the See also:

• ORGANS

organs one with another . It puts the organs into such mutual relation that the See also:

• ANIMAL
• ANIMAL (Lat. animalis, from anima, breath, soul)

animal reacts as a whole with See also:

• SPEED, JOHN (1552–1629)

speed, accuracy and self-See also:

• ADVANTAGE

advantage, in response to the environmental agencies which stimulate it . For this See also:

• OFFICE (from Lat. officium, " duty," " service," a shortened form of opifacium, from facere, " to do," and either the stem of opes, " wealth," " aid," or opus, " work ")

office of the nervous system there are two fundamental conditions . The system must be thrown into See also:

• ACTION

action by agencies at See also:

• WORK

work in the environment . See also:

• LIGHT

Light, gravity, See also:

• MECHANICAL

mechanical impacts, and so on, which are conditions significant for animal existence, must find the system responsive and through it evoke appropriate activity in the animal organs . And in fact there have been evolved in the animal a number of structures called receptive organs which are selectively excitable by different environmental agencies . Connected with these receptive organs lies that division of the nervous system which is termed afferent because it conducts impulses inwards towards the nervous centres .

This division consists of elongates] norve-Cells, in See also:

• MAN
• MAN, ISLE OF (anc. Mona)

man some two (Anthropopithecus 4°4 million in number for each See also:

• HALF

half of the body . These are living threads of microscopic tenuity, each extending from a receptive organ to a central nervous See also:

• MASS (O.E. maesse; Fr. messe; Ger. Messe; Ital. messa; from eccl. Lat. missa)
• MASS, IN

mass . These central nervous masses are in vertebrates all fused into one, of which the part which lies in the See also:

• HEAD (in 0. Eng. heafad; the word is common to Teutonic languages; cf. Dutch hoofd, Ger. Haupt, generally taken to be in origin connected with Lat. caput, Gr. KerbOvi7)
• HEAD, SIR EDMUND WALKER, BART
• HEAD, SIR FRANCIS BOND, BART

head is especially large and complex, because directly connected with particularly important and delicate receptive organs . The part of the central nervous organ which lies in the head has, in consequence of its connexion with the most important receptive organs, evolved a dominant importance in the nervous system, and this is especially true of the higher animal forms . This head part of the central nervous organ is sufficiently different from the See also:

• REST (O. Eng. rest, reste, bed, cognate with other Teutonic forms, e.g. Ger. Rast, Riiste, rest, and probably Gothic Rasta, league, i.e. resting or stopping place)

rest, even to anatomical examination, to have received a See also:

• SEPARATE

separate name, the brain . But the fact of its having received a separate name ought not to obscure the singleness and solidarity of the whole central nervous organ as one entity . The functions of the whole central nervous organ from region to region are essentially similar throughout . One of its essential functions is reception, via afferent nerves, of nervous impulses generated in the receptive organs by environmental agents as stimuli . In other words, whatever the nature of the See also:

• AGENT (from Lat. agere, to act)

agent, its result on the receptive organs enters the central nervous organ as a nervous impulse, and all segments of the central nervous organ receive impulses so generated . Further, it is not known that nervous impulses See also:

• PRESENT

present qualitative See also:

• DIFFERENCES, CALCULUS OF (Theory of Finite Differences)

differences among themselves . It is with these impulses that the central nervous organ whether See also:

• SPINAL

spinal cord or brain has to See also:

• DEAL

deal . Material and Psychical Signs of Cerebral Activity.—In the central nervous organ the action resulting from entrant impulses has issue in three kinds of ways .

The reaction may die out, be suppressed, and so far as discoverable See also:

• LEAD
• LEAD (pronounced iced)

lead to nothing; or the impulses may evoke effect in either or both of two forms . Just as from the receptive organs, nerves lead into the central nervous organ, so conversely from the central organ other nerves, termed efferent, lead to various organs of the body, especially glands and muscles . The reaction of the central nervous organ to impulses poured into it commonly leads to a See also:

• DISCHARGE (adapted from the O. Fr. discharge, modern decharge, from a med. Lat. discargare, to unload, dis- and earn care, to load, cf. " charge ")

discharge of impulses from it into glands and muscles . These centrifugal impulses are, so far as is known, qualitatively like the centripetal impulses . On reaching the glands and muscles they See also:

• INFLUENCE (Late Lat. influentia, from influere, to flow in)

influence the activity of those organs . Since those organs are therefore the mechanisms in which the ultimate effect of the nervous reaction takes See also:

• PLACE (through Fr. from Lat. platea, street; Gr. IrAar6s, wide)

place, they are often termed from this point of view effector organs . A See also:

• CHANGE (derived through the Fr. from the Late Lat. cambium, cambiare, to barter; the ultimate derivation is probably from the root which appears in the Gr. «a urmu', to bend)

change ensuing in effector organs is often the only sign an observer has. that a nervous reaction has occurred, unless the nervous system under observation be the observer's own . If the observer turns to his own nervous system for See also:

• EVIDENCE (Lat. evidentia, evideri, to appear clearly)

evidence of reaction, he meets at once in numberless instances with sensation as an outcome or sign of its reaction . This effect he cannot show to any being beside himself . He can only describe it, and in describing it he cannot strictly translate it into any See also:

• TERM

term of material existence . The unbridged gulf between sensation and the changes produced in effector organs necessitates a separate handling of the functions of the nervous system according as their office under See also:

• CONSIDERATION (from Lat. considerare, to look at closely, examine, generally taken to be from con-, and the base seen in sidus, sideris, a star, the word being supposed to be originally an astrological or astronomical term)

consideration is sensation or material effect . This holds especially in the See also:

• CASE
• CASE, JOHN (d. 1600)

case of the brain, and for the following reasons .

Psychosis and the Fore-Brain.—See also:

• HIPPOCRATES

Hippocrates wrote, " It is through the brain that we become mad, that See also:

• DELIRIUM (a Latin medical term for madness, from delirare, to be mad, literally to wander from the lira, or furrow)

delirium seizes us, that fears and terrors assail us." " We know that See also:

• PLEASURE (through Fr. plaisir from Lat. placere, to please; Gr. rlbovii)

pleasure and joy on the one See also:

• HAND
• HAND (a word common to Teutonic languages; cf. Ger. Hand, Goth. handus)
• HAND, FERDINAND GOTTHELF (1786-185r)

hand and See also:

• PAIN (from Lat. poena, Gr. robin, penalty, that which must be paid: O. Fr. peine)
• PAIN, BARRY (1867– )

pain and grief on the other are referable to the brain . It is in virtue of it that we think, understand, see, hear, know ugliness and beauty, evil and See also:

• GOOD, JOHN MASON (1764-1827)

good, the agreeable and the disagreeable." Similarly and more precisely See also:

• DESCARTES, RENE (1596-1650)

Descartes indicated the brain, and the brain alone, as the seat of consciousness . Finally, it was See also:

• FLOURENS, GUSTAVE (1838-1871)
• FLOURENS, MARIE JEAN PIERRE (1794-1867)

Flourens who perhaps first definitely insisted on the restriction of the seat of consciousness in higher animals to that part of the brain which is the fore-brain . A functional distinction between the fore-brain and the See also:

• REMAINDER, REVERSION

remainder of the nervous system seems, in fact, that consciousness and See also:

• PHYSICAL

physical reactions are See also:

• ADJUNCT (from Lat. ad, to, and jungere, to join)

adjunct to the fore-brain in a way in which they are not to the rest of the system . After transection of the[PHYSIOLOGY spinal cord, or of the brain behind the fore-brain, psychical phenomena do not belong to the reactions of the nervous arcs posterior to the transection, whereas they do still accompany reactions of the nervous arcs in front and still connected with the fore-brain . A man after severance of the spinal cord does not possess in the strict sense consciousness of the limbs whose afferent nerves See also:

• LIE, JONAS LAURITZ EDEMIL (1833—1908)
• LIE, MARIUS SOPHUS (1842–1899)

lie behind the place of spinal severance . He can see them with his eyes, and if the severance lie between the arms and the legs, can feel the latter with his hands . He knows them to be a part of his body . But they are detached from his consciousness . Sensations derived from them through all other channels of sense than their own do not suffice to restore them in any adequate measure to his consciousness . He must have the sensations so called " See also:

• RESIDENT

resident " in them, that, is, referred to them, without need of any logical inference . These can be yielded only by the receptive organs resident in the part itself, its skin, its See also:

• JOINTS

joints, its muscles, &c., and can only be yielded by those receptive organs so long as the nerve impulses from them have See also:

• ACCESS (Lat. accessus)

access to the fore-brain .

Consciousness, therefore, does not seem to attach to any portion of the nervous system of higher animals from which the fore-brain has been cut off . In the See also:

• DOG

dog it has been found that no sign of memory, let alone intelligence, has been forthcoming after removal of the greater part of the fore-brain . In lower vertebrates it is not clear that consciousness in primitive form requires always the co-operation of the fore-brain . In them the fore-brain does See also:

• RIOT (0. Fr. riote, of uncertain etymology)

riot seem a conditio sine qua non for psychosis—so far as we may See also:

• TRUST

trust the rather hazardous inferences which study of the behaviour of See also:

• FISH (O. Eng. fist, a word common to Teutonic languages, cf. Dutch visch, Ger. Fisch, Goth. fisks, cognate with the Lat. piscis)
• FISH, HAMILTON (1808-1893)

fish, &c., allows . And the difference between higher and lowlier animal forms in respect of the fore-brain as a See also:

• CONDITION (Lat. condicio, from condicere, to agree upon, arrange; not connected with conditio, from condere, conditum, to put together)

condition for psychosis becomes more marked when the See also:

• ARTHROPODA

Arthropoda are examined . The behaviour of some Insecta points strongly to their possessing memory, rudimentary in See also:

• KIND (O. E. ge-cynde, from the same root as is seen in " kin," supra)

kind though it may be . But in them no homologue of the fore-brain of vertebrates can be indisputably made out . The head ganglia in these Invertebrates may, it is true, be analogous in function in certain ways to the brain of vertebrates . Some experiments, not plentiful, indicate that destruction of these head ganglia induces deterioration of behaviour such as follows loss of psychical functions in cases of destruction of the fore-brain in vertebrates . Though, therefore, we cannot be clear that the head ganglia of these Invertebrates are the same structure morphologically as the brain of vertebrates, they seem to hold a similar office, exercising analogous functions, including psychosis of a rudimentary kind . We can, therefore, speak of the head ganglia of Arthropods as a brain, and in doing so must remember that we define by physiological evidence rather than by morphological . Cerebral See also:

• CONTROL (Fr. contrdle, older form contre rolle, from Med. Lat. contra-rotulus, a counter roll or copy of a document used to check the original; there is no instance in English of the use of " control " in this, its literal, meaning)

Control over Lower Nervous Centres.—There accrues to the brain, especially to the fore-brain of higher Vertebrates, another function besides that of grafting psychical qualities upon the reactions of the nervous system .

This function is exhibited as See also:

• POWER [WILLIAM GRATTAN] TYRONE (1797-1841)

power to control in greater or less measure the pure reflexes enacted by the system . These pure reflexes have the See also:

• CHARACTER (Gr. xapareri7p, from xap&crew, to scratch)

character of fatality, in the sense that, given a particular stimulus, a particular reaction unvaryingly follows; the same See also:

• GROUP

group of muscles or the same gland is invariably thrown into action in the same way . Removal of the fore-brain, i.e. of that portion of the central nervous organ to which psychosis is adjunct, renders the nervous reactions of the animal more predictable and less variable . The animal, for instance, a dog, is given over more completely to See also:

• SIMPLE

simple reflexes . Its skin is touched and it scratches the spot, its See also:

• JAW (Mid. Eng. jawe, jowe and geowe, O. Eng. cheowan, connected with " chaw " and " chew," and in form with " jowl ")

jaw is stroked and it yawns, its rump is rubbed and it shakes itself, like a dog coming out of See also:

• WATER

water; and these reactions occur fatally and inopportunely, for instance, when See also:

• FOOD
• FOOD (like the verb " to feed," from a Teutonic root, whence O. Eng. foda; cf. " fodder "; connected with Gr. lrareicOae, to feed)

food is being offered to it, when the dog normally would allow no such insignificant skin stimuli as the above to defer his appropriate reaction . See also:

• GOLTZ, BOGUMIL (18o1-1870)
• GOLTZ, COLMAR, FREIHERR VON DER (1843- )

Goltz relates the behaviour of a dog from which almost the whole fore-brain had been removed . The animal lived healthily under the careful treatment accorded it . At feeding See also:

• TIME (0. Eng. Lima, cf. Icel. timi, Swed. timme, hour, Dan. time; from the root also seen in " tide," properly the time of between the flow and ebb of the sea, cf. O. Eng. getidan, to happen, " even-tide," &c.; it is not directly related to Lat. tempus)
• TIME, MEASUREMENT OF
• TIME, STANDARD

time a little See also:

• QUININE

quinine (See also:

• BITTER, KARL THEODORE FRANCIS (1867– )

bitter) added to its sop of See also:

• MEAT

meat and See also:

• MILK (0. Eng. meoluc; from a common Indo-European root, cf. Lat. mulgere, Gr. ?t dXyetv)

milk led to the morsels, after being taken into the PHYSIOLOGY] mouth, being at once and regularly rejected . None was ever swallowed, nor was the slightest hesitation in their rejection ever obtained by any coaxing or command, or encouragement of the animal by the attendant who constantly had See also:

• CHARGE
• CHARGE (through the Fr. from the Late Lat. carricare, to load in a carrus or wagon; cf. " cargo ")

charge of it . On the other hand, directly an undoctored piece had entered the mouth it was swallowed at once . Goltz threw to his own See also:

• HOUSE
• HOUSE (O. Eng. hiss, a word common to Teutonic languages, cf. Dut. huis, Ger. Haus; in Gothic it is only found in gudhiss, a temple; it may be ultimately connected with the root of " hide," conceal)

house-dog a piece of the same doctored meat . The creature wagged its tail and took it eagerly, then after receiving it into its mouth pulled a wry See also:

• FACE (from Lat. fades, derived either from facere, to make, or from a root fa-, meaning " appear "; cf. Gr. cbatvstv)

face and hesitated, astonished .

But on encouragement to go on eating it the dog did so . Perhaps it deemed it unseemly to appear ungrateful to the giver and reject the See also:

• GIFT (a common Teutonic word, cf. Ger. die Gift, gift, das Gift, poison, formed from the Teut. stem gab-, to give, cf. Dutch geven, Ger. geben; in O. Eng. the word appears with initial y, the guttural of later English is due to Scandinavian influence)

gift . It overcame its reflex of rejection, and by its self-control gave See also:

• PROOF (in M. Eng. preove, proeve, preve, &°c., from O. Fr . prueve, proeve, &c., mod. preuve, Late. Lat. proba, probate, to prove, to test the goodness of anything, probus, good)

proof of the intact cerebrum it possessed . There seems a connexion between consciousness and the power to modify reflex action to meet the exigencies of the occasion . Pure reflexes are admirably adapted to certain ends . They are reactions which have long proved advantageous to the phylum of which the existent animal is the representative embodiment . But the reflexes have a See also:

• MACHINE
• MACHINE (through Fr. from Lat. form machina of Gr. µnxavil)

machine-like fatality, and conscious aim does not forerun their See also:

• EXECUTION (from Lat. ex-sequor, exsecutus, follow or carry out)

execution . The subject as active agent does not See also:

• DIRECT

direct them . Yet they lie under the control of higher centres . The cough, the eye-See also:

• CLOSURE (Fr. clooture)

closure, the impluse to smile, all these can be suppressed . The innate See also:

• RESPIRATORY

respiratory See also:

• RHYTHM (Greek pvBµds, from bap, to flow)

rhythm can be modified to meet the requirements of vocal utterance . In other words, the reaction of reflex arcs is controllable by the mechanism to whose activity consciousness is adjunct .

The reflexes controlled are often reactions but slightly affecting consciousness, but consciousness is very distinctly operative with the centres which exert the control . It may be that the See also:

• PRIMARY

primary aim, See also:

• OBJECT

object and purpose of consciousness is control . " Consciousness in a See also:

• MERE
• MERE, ADALBERT (1838-1909)

mere See also:

• AUTOMATON (from aurOs,self, and uiw, to seize)

automaton," writes See also:

• PROFESSOR (the Latin noun formed from the verb profiteri, to declare publicly, to acknowledge, profess)

Professor See also:

• LLOYD, EDWARD (1845— )
• LLOYD, WILLIAM (1627–1717)
• LLOYD, WILLIAM WATKISS (1813–1893)

Lloyd See also:

• MORGAN
• MORGAN, DANIEL (1736-1802)
• MORGAN, EDWIN DENNISON (1811-1883)
• MORGAN, JOHN HUNT (1825-1864)
• MORGAN, JOHN PIERPONT (1837–1913)
• MORGAN, LEWIS HENRY (1818-1881)
• MORGAN, SYDNEY, LADY (c. 1783-1859)
• MORGAN, THOMAS (d. 1743)

Morgan, " is a useless and unnecessary epiphenomenon." As to how this conscious control is operative on reflexes, how it intrudes its influence on the See also:

• RUNNING

running of the reflex machinery, little is known . The Cerebrum an Organ giving See also:

• ADAPTATION (from Lat. adaptare. to fit to)

Adaptation and Readjustment of Motor Acts.—The exercise of this control and the acquirement of skilled actions have obviously elements in See also:

• COMMON

common . By skilled actions, we understand actions not innately given, actions acquired by training in individual experience . The controlling centres pick out from an ancestral motor action some part, and isolate and enhance that until it becomes a skilled See also:

• ACT (Lat. actus, actum)

act . The motor co-ordination ancestrally provided for the See also:

• RING (O.E. hring; a word common to Teutonic languages; and probably cognate with the Lat. circus, Gr. KtpKOS or KpLKOS, Skt'. chakra, wheel, circle, cf. also " harangue "); in art, a band of circular shape of varying sizes, made of any material and used f

ring See also:

• FINGER

finger gives an extending of it only in See also:

• COMPANY

company with See also:

• EXTENSION (Lat. ex, out ; tendere, to stretch)

extension of the fingers on either See also:

• SIDE
• SIDE (mod. Eski Adalia)

side of it . The isolated lifting of the ring finger can, however, soon be acquired by training . In such cases the higher centre with conscious effort is able to dissociate a part from an ancestral co-ordination, and in that way to add a skilled adapted act to the See also:

• POWERS, HIRAM (1805-1873)

powers of the individual . The nervous organs of control form, therefore, a See also:

• SPECIAL

special See also:

• INSTRUMENT (Lat. instrumentum, from insincere, to build up, furnish, arrange, prepare)

instrument of adaptation and of readjustment of reaction, for better See also:

• ACCOMMODATION (Lat. accommodare, to make fit, from ad, to, cum, with, and modus, measure)

accommodation to requirements which may be new . The attainment of more precision and speed in the use of a See also:

• TOOL (0. Eng. tdl, generally referred to a root seen in the Goth. taujan, to make, or in the English word " taw," to work or dress leather)

tool, or the handling of a weapon, means a See also:

• PROCESS

process in which nervous organs of control modify activities of reflex centres themselves already perfected ancestrally for other though kindred actions . This process of learning is accompanied by conscious effort .

The effort consists not so much in any course of reasoning but rather in the acquiring of new sensorimotor experience . To learn See also:

• SWIMMING (from " swim," A.S. swimman, the root being common in Teutonic languages)

swimming or See also:

• SKATING (Dutch schaats, a skate)

skating by simple cogitation or mere visual observation is of course impossible . The new ideas requisite cannot be constructed without motor experience, and the training must include that motor experience . Hence the training for a new skilled motor manoeuvre must be simply ad hoc, and is of itself no training for another motor co-ordination . The more complex an organism the more points of contact does it have with its environment, and the more does it need readjustment amid an environment of shifting relationships . Hence the organs of consciousness and control, being organs of adaptation and readjustment of reaction, will be more pronounced the farther the animal See also:

• SCALE
• SCALE (1) A

scale is followed upward to its crowning See also:

• SPECIES

species, man . The cerebrum and especially the cerebral405 cortex may be regarded as the highest expression of the nervous organ of individual adaptation of reactions . Its high development in man makes him the most successful animal on See also:

• EARTH
• EARTH (a word common to Teutonic languages, cf. Ger. Erde, Dutch aarde, Swed. and Dan. jord; outside Teutonic it appears only in the Gr. 'pq'e, on the ground; it has been connected by some etymologists with the Aryan root ar-, to plough, which is seen in
• EARTH, FIGURE OF
• EARTH, FIGURE OF THE

earth's surface at the present See also:

• EPOCH (Gr. E7roxij, holding in suspense, a pause, from E1rxav, to hold up, to stop)

epoch . The most important part of all this See also:

• ADJUSTMENT (from late Lat. ad juxtare, derived from juxta, near, but early confounded with a supposed derivation from justus, right)

adjustment in his case, as he stands now, consists doubtless in that nervous activity which is intellectual . The mentality attached to his cerebrum includes reason in higher measure than is possessed by the mentality of other animals . He, therefore. more than they, can profitably forecast the future and act suitably to meet it from memory of the past . The cerebrum has proved itself by his case the most potent weapon existent for extending animal dominance over the environment .

Means and Present Aims of Physiological Study of the Brain.—The aspects of cerebral activity are therefore twofold . There is the contribution which it makes to the behaviour of the animal as seen in the creature's doings . On the other hand there is its product in the psychical See also:

• LIFE

life of the animal . The former of these is subject matter for physiology; the latter is especially the See also:

• PROVINCE
• PROVINCE (Lat. provincia; perhaps a contraction of providentia)

province of See also:

• PSYCHOLOGY
• PSYCHOLOGY (>Guxrl, the mind or soul, and X yos, theory)

psychology . Physiology does, however, concern itself with the psychical aspect of cerebral functions . Its See also:

• SCOPE (through Ital. scopo, aim, purpose, intent, from Gr. o'KOaos, mark to shoot at, aim, o ic07reiv, to see, whence the termination in telescope, microscope, &c.)

scope, embracing the study of the bodily organs in regard to function, includes the psychic as well as the material, because as just shown the former inextricably interlace with the latter . But the relation between the psychic phenomena and the working of the brain in regard to any data of fundamental or intimate character connecting the two remains practically as unknown to us as to the See also:

• GREEK
• GREEK, ETRUSCAN AND

Greek philosophers . What physiology has at present to be content with in this respect is the mere assigning of certain kinds of psychic events to certain See also:

• LOCAL

local regions of the cerebrum . This primitive quest constitutes the greater part of the " neurology " of our See also:

• DAY (O. Eng. dreg, Ger. Tag; according to the New English Dictionary, " in no way related to the Lat. dies")
• DAY, JOHN (1574-1640?)
• DAY, THOMAS (1748-1789)

day, and some advance has been made along its lines . Yet how meagre are really significant facts will be clear from the brief survey that follows . Before passing finally from these See also:

• GENERAL
• GENERAL (Lat. generalis, of or relating to a genus, kind or class)

general considerations, we may See also:

• NOTE
• NOTE (Lat. nota, mark, sign, from noscere, to know)

note that it becomes more and more clear that the brain, although an organ than can be treated as a whole, is complex in the sense that separable functions belong in some measure to its several parts . The means principally adopted in studying the functions of the brain—and it must be remembered that this study in its present phase is almost exclusively a mere See also:

• SEARCH, or VISIT AND SEARCH

search for localization —are four .

These are the physiological, the clinico-pathological, the histological and the zoological . The first named proceeds by observing the effects of artificial excitation, chiefly electric, of various parts of the brain, and the defects produced by destruction or removal of circumscribed portions . The clinicopathological proceeds by observing the disturbances of body and mind occurring in disease or injury, and ascertaining the extent of the disease or injury, for the most part See also:

• POST

post modem . The histological method examines the microscopic structure of the various regions of the brain and the characters and arrangement of the nerve-cells composing it . The zoological follows and compares the general features of the brain, as represented in the various types of animal creation . It is on the functions of the fore-brain that See also:

• INTEREST

interest now mainly focuses, for the reasons mentioned above . And the interest in the fore-brain itself chiefly attaches to the functions of its cortex . This is due to several causes . In man and the animals nearest him the cortex forms by far the larger part of the whole cerebral hemisphere . More than any other part it constitutes the distinctively human feature . It lies accessible to various experimental observations, as also to traumatic lesions and to the surgeon's See also:

• ART

art . It is composed of a great unbroken See also:

• SHEET

sheet of grey matter; for that reason it is a structure wherein processes of See also:

• PECULIAR

peculiar interest for the investigation in view are likely to occur .

To make this last inference more clear a reference to the See also:

• HISTOLOGY
• HISTOLOGY (Gr. Ler6c, web, tissue, properly the web-beam of the loom, from iQravai, to make to stand)

histology of nervous tissue must be made . The whole physiological function of the nervous system may be summed up in the one word " See also:

• CONDUCTION, ELECTRIC

conduction." This " conduction " may be defined as the transmission of states of excitement (nerve-impulses) along the neural arcs composing the system . The whole nervous system is built up of chains of nerve-cells (neurones) which are nervous conductors, the chains often 4.06 being termed arcs . Each neurone is an elongated See also:

• CELL (from Lat. cella, probably from an Indo-European kal —seen in Lat. celare, to hide; another suggestion connects the word with Lat. cera, wax, taking the original meaning to refer to the honeycomb)

cell which transmits nerve-impulses from its one end to its other, without so far as is known modifying the impulses in transit, unless in that part of the nerve-cell where the See also:

• NUCLEUS (Lat. for the kernal of a nut, nux, the stone of fruit)

nucleus lies . That part of the neurone or nerve-cell is called the perikaryon or cell-body, and from that part usually many branches of the cell (each See also:

• BRANCH (from the Fr. branche, late Lat. branca, an animal's paw)

branch being a nerve-fibre) ramify . There is no evidence that impulses are modified in transit along a branch of a nerve-cell, but there is clear evidence of manifold modification of nerve-impulses in transit along the nerve-arcs of the nervous system . These nerve-arcs are neurone-chains . In them one neurone continues the line of conduction where the immediately fore-going neurone See also:

• LEFT

left it . That is, the neurones are laid in conductive series, the far end of one apposed to the near end of its precursor . The place of juxtaposition of the end of one neurone against the beginning of another is called the synapse . At it the conduction which has so far been wholly See also:

• INTRA

intra-neuronic is replaced by an inter-neuronic process, in which the nerve impulse passes from one neurone to the next . The process there, it is natural to think, must be physiologically different from that conductive process that serves for transmission merely within the neurone itself .

It may be that to this inter-neuronic conduction are due the differences between conduction in nerve-arcs and nerve-trunks (nerve-fibres) respectively . Significant of the former are changes in rhythm, intensity, excitability and modifications by summation and See also:

• INHIBITION (from Lat. inhibere, to restrain, prevent)

inhibition; in fact a number of the See also:

• MAIN (from the Aryan root which appears in " may " and " might," and Lat. magnus, great)
• MAIN (Lat. Moenus)

main features of nervous reaction . These characters impressed upon conduction in nerve arcs (neurone-chains) would therefore be traceable to the intercalation of perikarya and synapses, for both these structures are absent from nerve-trunks . It is therefore probably to perikarya and synapses that the greater part of the co-ordination, elaboration and differentiation of nervous reactions is due . Now, perikarya and synapses are not present in the white matter of the central nervous organ, any more than they are in nerve-trunks . They are confined exclusively to those portions of the central organ which consist of grey matter (so called from its naked-eye See also:

• APPEARANCE (from Lat. apparere, to appear)

appearance) . Hence it is to the great sheet of grey matter which enfolds the cerebrum that the physiologist turns, as to a See also:

• FIELD (a word common to many West German languages, cf. Ger. Feld, Dutch veld, possibly cognate with O.E. f olde, the earth, and ultimately with root of the Gr. irAaror, broad)
• FIELD, CYRUS WEST (1819-1892)
• FIELD, DAVID DUDLEY (18o5-1894)
• FIELD, EUGENE (1850-1895)
• FIELD, FREDERICK (18o1—1885)
• FIELD, HENRY MARTYN (1822-1907)
• FIELD, JOHN (1782—1837)
• FIELD, MARSHALL (183 1906)
• FIELD, NATHAN (1587—1633)
• FIELD, STEPHEN JOHNSON (1816-1899)
• FIELD, WILLIAM VENTRIS FIELD, BARON (1813-1907)

field where he would expect to find evidences of the processes of cerebral co-ordination at work . It is therefore to items regarding the functions of the great sheet of cerebral cortex that we may now pass . The Cerebral Cortex and its Functions.—The main question which vexed the study of the physiology of the cerebral hemispheres in the 19th See also:

• CENTURY (from Lat. centuria, a division of a hundred men)

century was whether differences of function are detectible in the different regions of the hemisphere and especially in those of its cortex . One See also:

• CAMP (from Lat. campus, field)

camp of experimenters and observers held that the cortex was identical in function throughout its extent . These authorities taught that the various faculties and senses suffer damage in proportion to the amount of cortex removed or injured, and that it is a matter of indifference what may be the particular region wherein the destruction takes place . Against this an opposed set of observers held that different regions perform different functions, and this latter " See also:

• DIFFERENTIAL

differential " view was raised in two wholly dissimilar forms in the first and last quarters of the 19th century respectively .

In the first See also:

• QUARTER (through Fr. from Lat. quartarius, fourth part)

quarter of the century, a school, with which the name of See also:

• GALL (a word common to many Teutonic languages, cf. Dutch gal, and Ger. Galle; the Indo-European root appears in Gr. xoXi,, and Lat. fel; possibly connected with " yellow," with reference to the colour of bile)
• GALL, FRANZ JOSEPH (1758-1828)

Gall is prominently associated, held that each See also:

• FACULTY (through the French, from the Lat. facultas, ability to do anything, from facilis, easy, facere, to do; another form of the word in Lat. facilitas, facility, ease, keeps the original meaning)

faculty of a set of particular so-called " faculties," which it assumed constituted intelligence, has in the brain a spatially separate organ proper to itself . Gall's See also:

• DOCTRINE

doctrine had two fundamental propositions . The first was that intelligence resides exclusively in the brain: the second, that intelligence consists of twenty-seven " faculties," each with a separate local seat in the brain . The first proposition was not new . It is met with in Hippocrates, and it had been elaborated by Descartes and others . But See also:

• BICHAT, MARIE FRANCOIS XAVIER (1771–1802)

Bichat in his Anatomie generale had partly wandered from the gradually established truth and referred the emotions to the visceral organs, returning to a naive view popularly prevalent . Gall's first proposition was probably raised especially in reaction against Bichat . But Gall's proposition was See also:

• RETROGRADE (from the Lat. retro, backwards, gradiri, to go)

retrograde from the true position of the See also:

• SCIENCE (Lat. scientia, from scire; to learn, know)

science of his time . Flourens[PHYSIOLOGY and others of his contemporaries had already shown not only that intelligence was resident exclusively in the brain, but that it was resident exclusively in that part of the brain which is the fore-brain . Now Gall placed certain of his twenty-seven intellectual faculties in the cerebellum, which is part of the See also:

• HIND

hind-brain . See also:

• PHRENOLOGY, (from Gr. OOP, mind, and Xbyos, discourse)

Phrenology.—As to Gall's second proposition, the set of faculties into which he analysed intelligence shows his power of psychological See also:

• ANALYSIS (Gr. avci and Meta, to break up into parts)

analysis to have been so weak that it is matter of surprise his doctrine could obtain even the ephemeral See also:

• VOGUE, EUGENE MELCHIOR, COMTE DE (1848- )

vogue it actually did . Among his twenty-seven faculties are, for instance, " l'amour de la progeniture, l'See also:

• INSTINCT

instinct carnassier, l'amitie, la ruse, la sagacite See also:

• COMPARATIVE

comparative, l'esprit metaphysique, le See also:

• TALENT (Lat. talentum, adaptation of Gr. TaXavrov, balance, ! Recollections of a First Visit to the Alps (1841); Vacation Rambles weight, from root raX-, to lift, as in rXi vac, to bear, 1-aXas, and Thoughts, comprising recollections of three Continental

talent poetique, la mimique," &c .

Such crudity of See also:

• SPECULATION

speculation is remarkable in one who had undoubtedly considerable insight into human character . Each of the twenty-seven faculties had its seat in a part of the brain, and that part of the brain was called its " organ." The mere spatial juxtaposition or remoteness of these organs one from another in the brain had, according to Gall, an influence on the constitution of the mind . " Comme l'organe des arts est place See also:

• LOIN (through O. Fr. loigne or logne, mod. lunge, from Lat. Iambus)

loin de l'organe du See also:

• SENS

sens des couleurs, See also:

• CETTE

cette circonstance explique pourquoi See also:

• LES

les peintres d'histoire ont etc rarement coloristes." All these " faculty-organs " were placed by Gall at the surface of the brain . " This explains the See also:

• CORRESPONDENCE
• CORRESPONDENCE (from med. scholastic Lat. correspondentia, corrcspondere, compounded of Lat. cum, with, and respond ere, to answer; cf. Fr. correspondance)

correspondence which exists between craniology and the doctrine of the functions of the brain (cerebral physiology), the single aim of my researches." Gall wrote that he found the bump of See also:

• PRIDE, THOMAS (d. 1658)

pride (la bosse de l'orgueil) as far down in the animal series as the See also:

• GOAT (a common Teut. word; O. Eng. gat, Goth. gaits, Mod. Ger. Geiss, cognate with Lat. haedus, a kid)

goat . See also:

• BROUSSAIS, FRANCOIS JOSEPH VICTOR (1772-1838)

Broussais traced the " organ " of veneration as far down as the See also:

• SHEEP
• SHEEP (from the Anglo-Saxon sceap, a word common in various forms to Teutonic languages; e.g. the German Schaf)

sheep . Gall found the bump of See also:

• MURDER

murder (bosse du meurtre) in the See also:

• CARNIVORA

carnivora . Later it was traced also in herbivora . Broussais added apologetically that " the herbivora cause a real destruction of See also:

• PLANTS

plants." Gall's doctrine enjoyed enormous vogue . He himself had the gifts and the demerits of quackery . His doctrine possessed, apart from its falsity, certain other mischievous qualities . " Que See also:

• CES

ces hommes si glorieux, qui See also:

• FONT (Lat. fans, " fountain " or " spring," Ital. fonte, Fr. les fonts)

font egorger les nations See also:

• PAR (Lat. par, equal)

par millions, sachent qu'ils n'agissent point de leur propre chef, que c'est la nature qui a place clans leur cceur la rage de la destruction." One of his scientific opponents rejoined, " See also:

• NAY, or NEY

Nay, it is not that which they should know . What they should know is that if See also:

• PROVIDENCE

providence has allowed to man the possibility of doing evil, it has also endowed him with the power to do good." The main cause of the success of phrenology (q.v.) has been no doubt the common See also:

• DESIRE

desire of men to read the characters and hidden thoughts of others by external signs .

Each bump or "bosse " on the cranium was supposed to indicate the existence and degree of development of one or other of the twenty-seven " faculties." One such " bosse " showed the development of the organ of " goodness," and another the development of the organ of " murder." Such an easy means to arrive at See also:

• INFORMATION (from Lat. informare, to give shape or form to, to represent, describe)

information so curious delighted many persons, and they were not willingly undeceived . See also:

• MODERN

Modern Localization Doctrines.—The crude localization of the phrenologists is therefore too clumsy to possess an interest it might otherwise have had as an early expression of belief in cerebral localization, a belief which other labours have subsequently justified, although on facts and lines quite different from these imagined by Gall'and his followers . Patient scientific toil by the hands of E . See also:

• HITZIG, FERDINAND (1807-1875)

Hitzig and D . See also:

• FERRIER, ARNAUD DU (c. 1508-1585)
• FERRIER, JAMES FREDERICK (1808-1864)
• FERRIER, PAUL (1843– )
• FERRIER, SUSAN EDMONSTONE (1782–1854)

Ferrier and their followers has slowly succeeded in obtaining certain facts about the cortex cerebri which not only show that different regions of it are concerned with different functions, but, for some regions at least, outline to some extent the kind of function exercised . It is true that the greater part of the cortex remains still terra incognita unless we are content with'mere descriptive features concerning its coarse See also:

• ANATOMY
• ANATOMY (Gr. avaroyil, from ava-silo c', to cut up)

anatomy . For several scattered regions some knowledge of their function has been gained by physiological investigation . These scattered regions are the visual, the auditory, the olfactory and the precentral . The grey matter of the cerebral cortex is broadly characterized histologically by the perikarya (nerve-cells bodies) which lie in it PHYSIOLOGY) possessing a special shape; they are pyramidal . The dendrite fibres of these cells—that is, their fibres which conduct towards the perikarya—are branches from the See also:

• APEX

apex and corners of the See also:

• PYRAMID

pyramid . From the base often near its middle arises one large fibre—the axone fibre, which conducts impulses away from the perikaryon . The general appearance and arrangement of the neurones in a particle of cortical grey matter are shown in fig .

15, above . The apices of the pyramidal perikarya are turned towards the See also:

• FREE

free surface of the cortex . The figure as interpreted in terms of functional conduction means that the cortex is beset with conductors, each of which collects nerve-impulses, from a See also:

• MINUTE
• MINUTE (Lat. minutes, small; minuere, to make less)

minute but relatively wide field by its branched dendrites, and that these nerve-impulses converge through its perikaryon, issue by its axone, and are carried whithersoever the axone runs . In some few cells the axone breaks up into branches in the immediate neighbourhood of its own perikaryon in the cortex . In most cases, however, the axone runs off into the subjacent white matter, leaving the cortex altogether . On reaching the subjacent white matter it mingles with other fibres and takes one of the following courses:—(r) to the grey matter of the cortex of the same hemisphere, (2) to the grey matter of the cortex of the opposite hemisphere, (3) to the grey matter of the pons, (4) to the grey matter of the bulb or spinal cord . It is noteworthy that the dendrite fibres of these cortical neurones do not transgress the limits of the grey cortex and the immediate See also:

• NEIGHBOUR (O. Eng. neahgebiir, from Walt, " nigh," " near ")

neighbour-See also:

• HOOD,
• HOOD, JOHN BELL (1831–1879)
• HOOD, SAMUEL HOOD, VISCOUNT (1724–1816)
• HOOD, SIR SAMUEL (1762-1814)
• HOOD, THOMAS (1799-1845)
• HOOD, TOM (1835–1874)

hood of the perikaryon to which they belong; whereas the discharging or axone fibre does in the vast See also:

• MAJORITY (Fr. majorite; Med. Lat. majoritas; Lat. major, greater)

majority of cases transgress the limits of the grey matter wherein its perikaryon lies . The cortical neurone therefore collects impulses in the region of cortex just about its perikaryon and discharges them to other regions, some not cortical or even cerebral, but spinal, &c . One question which naturally arises is, do these cells spontaneously generate their impulses or are they stirred to activity by impulses which reach them from without ? The tendency of physiology is to regard the actions of the cortex as reactions to impulses communicated to the cortical cells by nerve-channels reaching them from the sense organs . The neurone conductors in the cortex are in so far considered to resemble those of reflex centres, though their reactions are more variable and complex than in the use of the spinal . The chains of neurones passing through the cortex are more complex and connected with greater See also:

• NUMBERS, BOOK OF
• NUMBERS, PARTITION OF

numbers of See also:

• ASSOCIATE (Lat. associates, from ad, to, and sociare to join)

associate complex chains than are those of the spinal centres .

But just as the reflex centres of the cord are each attached to afferent channels arriving from this or that receptive-organ, for instance, tactile-organs of the skin, or spindles of muscle-sense, &c., so the regions of cortex whose function is to-day with some certainty localized seem to be severally related each to some particular sense-organ . The localization, so far as ascertained, is a localization which attaches separate areas of cortex to the several species of sense, namely the visual, the auditory, the olfactory, and so on . This being so, we should expect to find the sensual See also:

• REPRESENTATION

representation in the cortex especially marked for the organs of the great distance-receptors, the organs which—considered as sense organs—initiate sensations having the quality of projicience into the sensible environment . The organs of distance-receptors are the olfactory, the visual and the auditory . The environmental agent which acts as stimulus in the case of the first named is chemical, in the second is radiant, and in the last is mechanical . Olfactory Region of Cortex.—There is phylogenetic evidence that the development of the cortex cerebri first occurred in connexion with the distance-receptors for chemical stimuli—that is, expressed with reference to psychosis, in connexion with olfaction . The olfactory apparatus even in mammals still exhibits a neural See also:

• ARCHITECTURE (Lat. architectura, from the Gr. ap)(LTEKrwv, a master-builder)

architecture of primitive See also:

• PATTERN

pattern . The cell which conducts impulses to the brain from the olfactory membrane in the See also:

• NOSE (O.Eng. nosu, cf. Dutch neus, Swed. nos, snout; the Aix in Provence. Both at Aix and at Lyons he acquired great connexion with O.Eng. nasu is obscure, cf. Ger. Nase, Lat. pares, distinction by his labours during outbreaks of the plague. In nostrils,

nose resembles cells in the skin of the See also:

• EARTHWORM

earthworm, in that its cell-body lies actually amid the epithelium of the skin-surface and is not deeply buried near or in the central nervous organ . Further, it has at its external end tiny hairlets such as occur in specially receptive-cells but not usually in purely nervous cells . Hence we must think that one and the same cell by its external end407 receives the environmental stimulus and by its deep end excites the central nervous organ . The cell under the stimulation of the environmental agent will therefore generate in itself a nervous impulse . This is the clearest instance we have of a neurone being actually excited under natural circumstances by an agent of the environment directly, not indirectly .

The deep ends of these olfactory neurones having entered the central nervous organ come into contact with the dentrites of large neurones, called, from their shape, mitral . In the dog, an animal with high olfactory sense, the axone of each olfactory neurone is connected with five or six mitral cells . In man each olfactory neurone is connected with a single mitral cell only . We may suppose that the former arrangement conduces to intensification of the central r