Chapter I: Part 1

TEXT BOOK
OF
VETERINARY MEDICINE

BY

JAMES LAW, F.R.C.V.S.

Director of the New York State Veterinary College Cornell University,
Ithaca, N.Y.

VOL. III

DISEASES OF THE NERVOUS SYSTEM—GENITO-URINARY ORGANS—EYE—SKIN
CONSTITUTIONAL DISEASES

ITHACA
PUBLISHED BY THE AUTHOR
1901

Copyright by
JAMES LAW
1901

PRESS OF
ANDRUS & CHURCH
ITHACA, N. Y.

CONTENTS

DISEASES OF THE NERVOUS SYSTEM.
GENERAL SYMPTOMATOLOGY AND DIAGNOSIS.
TROPHIC SYMPTOMS AND DISORDERS.
SENSORY SYMPTOMS AND DISORDERS.
PSYCHIC SYMPTOMS AND DISORDERS.
DIAGNOSIS, SYMPTOMS AND THEIR IMMEDIATE CAUSES. LOCALIZATION OF LESION
IN SPECIAL SYMPTOMS.
HALLUCINATIONS.
TIMIDITY. PANIC. STAMPEDE.
BALKING. RESTIVENESS.
DELIRIUM.
VICIOUSNESS. AGGRESSIVE VICE.
CATALEPSY.
INSOLATION. HEAT EXHAUSTION. SUNSTROKE. THERMIC FEVER.
EPILEPSY. FALLING SICKNESS.
ECLAMPSIA. CONVULSIONS. SPASMS.
CHOREA. ST. VITUS DANCE.
CONVULSIVE TWITCHING OF THE FACE.
VERTIGO. MEGRIMS. BLIND STAGGERS.
CONCUSSION OF THE BRAIN.
LIGHTNING STROKE. ELECTRIC SHOCK.
INTRACRANIAL HÆMORRHAGE AND THROMBOSIS. APOPLEXY. SOFTENING OF THE
BRAIN.
CEREBRAL HYPERÆMIA. MENINGO—ENCEPHALIC CONGESTION.
MENINGO—ENCEPHALITIS. STAGGERS.
CHRONIC HYDROCEPHALUS. DROPSY OF THE VENTRICLES. IMMOBILITY.
CEREBRO-SPINAL MENINGITIS.
ABSCESS OF THE BRAIN.
TUBERCULAR MENINGITIS.
TUMORS OF THE BRAIN. NEOPLASMS.
CHOLESTEATOMA.
MELANOMA OF THE ENCEPHALON.
PSAMMOMATA (GRITTY TUMORS) OF THE BRAIN.
MYXOMA OF THE BRAIN.
ACROMEGALY. HYPERTROPHY OF THE PITUITARY BODY.
CEREBELLAR DISEASE.
BULBAR PARALYSIS. DISEASE OF MEDULLA OBLONGATA.
LOCO POISONING. OXYTROPIS LAMBERTI. ASTRAGALUS MOLLISSIMUS
LEAD POISONING. PLUMBISM.
ALCOHOLIC INTOXICATION.
ANILINE POISONING.
POISONING BY NITRO-BENZOL.
POISONING BY CARBON DISULPHIDE.
TETANY.
CONGESTION OF THE SPINAL CORD IN THE HORSE AND COW.
ACUTE MYELITIS. POLIOMYELITIS. INFLAMMATION OF THE SPINAL CORD.
SPINAL MENINGITIS.
ACUTE MYELITIS IN THE DOG. MENINGO-MYELITIS.
CHRONIC MYELITIS. SCLEROSIS.
ARTERITIS (THROMBOSIS, EMBOLISM) OF THE SPINAL CORD AND MEMBRANES.
HEMORRHAGES INTO THE SPINAL MEMBRANES. Meningeal Spinal Apoplexy.
Hæmatorrachis. Hemorrhage into the Spinal Cord. Spinal Apoplexy.
Hæmatomyelia.
SPINA BIFIDA.
SPINAL CARIES. TUBERCULAR OR OTHER INFECTIVE DISEASE OF THE VERTEBRÆ.
SLOW COMPRESSION OF SPINAL CORD. PARALYSIS.
DILATATION OF THE CENTRAL CANAL OF THE SPINAL CORD. SYRINGOMYELIA.
NEURASTHENIA IN PREGNANT EWES.
NEURITIS. PERINEURITIS.
NEURALGIA.
ATROPHY OF NERVES.
DISEASES OF THE URINARY ORGANS.
PHYSICAL PROPERTIES OF THE URINE.
GENERAL SYMPTOMS OF URINARY DISEASE.
HEMATURIA.
ACUTE CONGESTION OF THE KIDNEYS IN SOLIPEDS.
ACUTE CONGESTION OF THE KIDNEYS IN CATTLE.
ACUTE CONGESTION OF THE KIDNEYS IN SHEEP AND GOAT.
ACUTE CONGESTION OF THE KIDNEYS IN SWINE.
CONGESTION OF THE KIDNEYS IN CARNIVORA.
NEPHRITIS.
ACUTE NEPHRITIS. ACUTE BRIGHT’S DISEASE.
PURULENT NEPHRITIS.
PERINEPHRITIS.
PYELITIS. PYELONEPHRITIS. INFLAMMATION OF THE RENAL PELVIS.
CHRONIC NEPHRITIS.
HYPERTROPHY OF THE KIDNEY.
ATROPHY OF THE KIDNEY.
FATTY DEGENERATION OF THE KIDNEY
AMYLOID KIDNEY. LARDACEOUS OR WAXY KIDNEY.
RENAL CALCULUS.
INJURIES OF THE URETERS.
URETERITIS.
ACUTE CATARRHAL CYSTITIS.
ACUTE CROUPOUS CYSTITIS.
CHRONIC CATARRHAL CYSTITIS.
CYSTITIS IN THE OX.
CYSTITIS IN DOGS.
ATONY AND PARALYSIS OF THE BLADDER.
TUMORS OF THE BLADDER.
VESICAL PARASITES.
SPASM OF NECK OF BLADDER.
RUPTURE AND LACERATION OF THE BLADDER.
EVERSION OF THE BLADDER.
HERNIA OF THE BLADDER.
ANOMALIES OF THE BLADDER.
URETHRAL ANOMALIES.
ACUTE URETHRITIS. CATARRH OF THE URETHRA.
WOUNDS OF THE URETHRA.
FOREIGN BODIES IN THE URETHRA.
STRICTURE OF THE URETHRA.
ACUTE PROSTATITIS AND HYPERÆMIA OF THE PROSTATE.
CHRONIC PROSTATITIS.
HYPERTROPHY OF THE PROSTATE.
TUBERCULOSIS OF THE PROSTATE.
CANCER OF THE PROSTATE.
PROSTATIC CYSTS.
CALCULUS OF THE PROSTATE.
DISEASES OF THE FEMALE GENERATIVE ORGANS. Malposition of ovary and
womb. Hernia of the ovaries.
UNDEVELOPED OVARIES. ABSENCE OF OVARIES.
ATROPHY OF OVARIES.
SUPERNUMERARY OVARIES.
IRRITABLE OVARY. NEURALGIA OF THE OVARY.
HÆMORRHAGE ON THE OVARY.
INFLAMMATION OF THE OVARIES. OÖPHORITIS. PERIOÖPHORITIS.
OVARIAN CYSTS.
DERMOID CYSTS OF THE OVARY. PILOUS CYSTS.
SOLID OVARIAN TUMORS.
INFLAMMATION OF THE FALLOPIAN TUBES. SALPINGITIS.
DISEASES OF THE OVIDUCT IN BIRDS.
HYDROMETRA AND PYOMETRA.
UTERINE TUMORS.
UTERINE TUBERCLE.
IMPERFORATE HYMEN.
VAGINITIS. LEUCORRHŒA.
TUMORS OF THE VAGINA.
PARTURITION FEVER (COLLAPSE). MILK FEVER. PARTURIENT APOPLEXY. CALVING
FEVER. PARTURITION PARESIS.
DISEASES OF THE EYE. DESIRABLE FEATURES IN THE EYE.
DEFECTS, BLEMISHES AND ABNORMALITIES OF THE HORSE’S EYE.
SYSTEMATIC INSPECTION OF THE EYE.
OPHTHALMOSCOPE.
WOUNDS OF THE EYELIDS.
DEFICIENCY OF THE EYELIDS. COLOBOMA PALPEBRARUM.
ORGANIC UNION OF THE EYELIDS. ANKYLOBLEPHARON. NARROWED FISSURE
BETWEEN THE LIDS. BLEPHAROPHYMOSIS.
WIDENED PALPEBRAL FISSURE.
LAGOPHTHALMOS. INABILITY TO CLOSE EYELIDS.
ADHESION OF THE EYELID TO THE BULB. SYMBLEPHARON.
INFLAMMATION OF THE EYELIDS. BLEPHARITIS.
ŒDEMA OF EYELIDS.
EMPHYSEMA OF THE EYELIDS.
DISEASE OF THE MEIBOMIAN GLANDS. BLEPHARADENITIS. SEBORRHŒA.
HORDEOLUM. STYE. ACNE.
CHALAZION.
TUBERCULOSIS OF THE EYELID.
TURNED IN EYELASH. TRICHIASIS.
ENTROPION. TURNING IN OF THE EYELID.
TURNING OUT OF THE EYELID. ECTROPION.
TUMORS OF THE EYELIDS.
FRACTURE OF THE ORBIT.
BRUISES AND WOUNDS OF THE ORBIT.
RETRO-BULBAR ABSCESS.
PERIOSTITIS OF THE ORBIT.
TUMORS OF THE ORBIT.
DISEASE OF THE LACHRYMAL GLAND AND DUCTS. DACRYO-ADENITIS.
OBSTRUCTION OF THE LACHRYMAL PUNCTA. ATRESIA. INFLAMMATION.
WOUND AND FISTULA OF THE LACHRYMAL SAC.
CATARRH OF THE LACHRYMAL SAC. DACRYOCYSTITIS.
STENOSIS OF THE LACHRYMO-NASAL DUCT.
DISEASE OF THE LACHRYMAL CARUNCLE.
WOUNDS AND INFLAMMATION OF THE MEMBRANA NICTITANS.
TUMORS AND HYPERTROPHY OF THE MEMBRANA NICTITANS.
ADENOMA OF THE GLAND OF HARDER.
FOREIGN BODIES IN THE CONJUNCTIVAL SAC.
WOUNDS OF THE CONJUNCTIVA.
BURNS OF THE CONJUNCTIVA.
SIMPLE ACUTE CATARRHAL CONJUNCTIVITIS.
CHRONIC CONJUNCTIVITIS.
PURULENT CONJUNCTIVITIS. BLENNORRHŒA.
INFECTIOUS CONJUNCTIVITIS IN HERBIVORA. ENZOOTIC OPHTHALMIA.
VARIOLOUS CONJUNCTIVITIS.
APHTHOUS CONJUNCTIVITIS. PHLYCTENULAR CONJUNCTIVITIS.
DIPHTHERITIC CONJUNCTIVITIS IN BIRDS.
FOLLICULAR CONJUNCTIVITIS.
NEOPLASMS OF THE CONJUNCTIVA.
PTERYGIUM.
XEROSIS CORNEÆ (EPITHELIALIS). DRY KERATITIS.
WOUNDS OF THE CORNEA.
FOREIGN BODIES IN THE CORNEA.
ACUTE KERATITIS. INFLAMMATION OF THE CORNEA.
POISONING WITH COTTON SEED OR COTTON SEED MEAL.
CHRONIC KERATITIS.
OPACITY OF THE CORNEA. NEBULA. MACULA. LEUCOMA.
ULCER OF THE CORNEA.
CORNEAL STAPHYLOMA.
ECTASIA CORNEÆ. KERATOCONUS. CONICAL CORNEA.
KERATOGLOBUS.
TUMORS OF THE CORNEA.
WOUNDS OF THE SCLERA.
EPISCLERITIS. INFLAMMATION OF THE SCLERA.
ECTASIA (BULGING) OF THE SCLERA.
PROLAPSE OF THE IRIS.
INTERNAL OPHTHALMIA.
SIMPLE IRITIS.
SYMPTOMATIC OR METASTATIC IRITIS.
FOREIGN BODIES IN THE IRIS.
COLOBOMA IRIDIS. CONGENITAL APERTURE IN IRIS.
DOUBLE PUPIL.
ALBINISM. WATCH EYE.
PERSISTENT PUPILLARY MEMBRANE.
OCCLUDED PUPIL.
CYCLITIS.
CYSTS OF THE IRIS AND CORPORA NIGRA.
TUBERCULOSIS OF THE IRIS.
CHOROIDITIS.
DETACHMENT OF THE CHOROID.
RECURRENT OPHTHALMIA OF SOLIPEDS. PERIODIC OPHTHALMIA. MOONBLINDNESS.
PANOPHTHALMITIS.
GLAUCOMA.
EXOPHTHALMOS.
HYDROPHTHALMOS OR BUPHTHALMUS CONGENITUS.
CATARACT. OPACITY OF THE LENS OR ITS CAPSULE.
DISLOCATION OF THE LENS.
PERSISTENT ARTERIA HYALOIDEA.
OPACITY OF THE VITREOUS.
RETINITIS.
DETACHMENT OF THE RETINA.
RETINAL HEMORRHAGE.
TUMORS OF THE RETINA.
INFLAMMATION OF THE OPTIC NERVE. PAPILLITIS.
RETRO-BULBAR OPTIC NEURITIS.
ATROPHY. PARALYSIS OF THE OPTIC NERVE. AMBLYOPIA. AMAUROSIS.
ANOPHTHALMOS. ATROPHY OF THE EYEBALL. PHTHISIS BULBI. MICROPHTHALMOS.
LUXATIO BULBI. DISLOCATION OF THE GLOBE OF THE EYE.
ARTIFICIAL EYE.
STRABISMUS. SQUINTING. LACK OF MUSCULAR BALANCE.
NYSTAGMUS. OSCILLATORY MOVEMENT OF THE EYE.
DISEASES OF THE SKIN.
GENERAL CAUSES OF SKIN DISEASES.
DIAGNOSIS OF SKIN DISEASES.
GENERAL PRINCIPLES OF TREATMENT OF SKIN DISEASES.
ERYTHEMA. ERYTHEMATOUS DERMATITIS.
INTERTRIGO. INTERTRIGO OF CHAFING.
ERYTHEMA CALORICUM
BUCKWHEAT ERYTHEMA
ERYTHEMA FROM IRRITANTS.
DERMATITIS.
ECZEMA. A BOILING OUT. A PUSTULE.
ACUTE ECZEMA IN SOLIPEDS. DORSAL ASPECT.
CHRONIC ECZEMA OF THE HEAD IN SOLIPEDS.
CHRONIC MOIST ECZEMA (IMPETIGO) AT THE MANE AND TAIL.
CHRONIC ECZEMA OF THE CARPUS AND TARSUS; MALANDERS
ECZEMA OF ALIMENTARY ORIGIN IN CATTLE. STARVATION MANGE. STALK
DISEASE. MALT ECZEMA. POTATO ECZEMA.
MOIST ECZEMA OF THE PASTERNS IN THE OX.
MOIST ECZEMA OF THE TAIL, NECK, CHINE AND DEWLAP OF CATTLE.
CHRONIC ECZEMA IN CATTLE.
ECZEMA IN SHEEP.
ECZEMA IN SWINE.
VESICULAR IRRUPTION IN PIGS. PITCHY AFFECTION. SEBORRHŒA.
GRANULAR ERUPTION IN SWINE.
ACUTE ECZEMA OF THE DOG.
OTHER ACUTE ECZEMAS IN DOGS.
CHRONIC ECZEMA IN THE DOG.
LICHEN. HEAT PAPULES. PRICKLY HEAT.
PITYRIASIS
PITYRIASIS IN CATTLE.
PITYRIASIS IN THE DOG AND CAT.
CONTAGIOUS PUSTULAR DERMATITIS IN THE HORSE. ACNE.
PEMPHIGUS IN HORSE, OX, PIG AND DOG.
CRACKED HEELS IN HORSES. SCRATCHES.
SEBORRHŒA OF THE DIGITAL REGION
CUTANEOUS HEMORRHAGE
ULCERATION. GANGRENE. BED SORES.
CUTANEOUS HYPERTROPHY. ELEPHANTIASIS. PACHYDERMIA.
ICHTHYOSIS. FISH-SKIN DISEASE.
FURUNCULUS. BOIL.
HYPERPLASIA OF THE SKIN.
ALOPECIA CONGENITA. CONGENITAL BALDNESS.
ALOPECIA. POST PARTEM. ALOPECIA AREATA.
TRICHORRHEXIS NODOSA. NODULAR SWELLING AND SPLITTING OF HAIR.
CONSTITUTIONAL DISEASES. RHEUMATISM.
SYMPTOMS OF ACUTE ARTICULAR RHEUMATISM IN THE HORSE.
SYMPTOMS OF CHRONIC ARTICULAR RHEUMATISM IN THE HORSE.
SYMPTOMS OF MUSCULAR RHEUMATISM IN HORSES.
SYMPTOMS OF ACUTE ARTICULAR RHEUMATISM IN CATTLE.
SYMPTOMS OF MUSCULAR RHEUMATISM IN CATTLE.
SYMPTOMS OF RHEUMATISM IN SHEEP.
SYMPTOMS OF ARTICULAR RHEUMATISM IN SWINE.
SYMPTOMS OF ARTICULAR RHEUMATISM IN THE DOG.
SYMPTOMS OF MUSCULAR RHEUMATISM IN THE DOG.
PREVENTION AND TREATMENT OF RHEUMATISM.
GOUT. PODAGRA. ARTHRITIS URICA.
SCURVY
GOITRE. BRONCHOCELE. ENLARGEMENT OF THE THYROID.
EXOPHTHALMIC GOITRE.
RACHITIS. RICKETS.
BRAN DISEASE
OSTEO-MALACIA (MALAXOS SOFT)
RAREFYING OSTEITIS. OSTEOPOROSIS. OSTEO-MALACIA OF THE HORSE. BIG
HEAD.
OSTEO-MALACIA IN OTHER ANIMALS.
INDEX.

VETERINARY MEDICINE.

DISEASES OF THE NERVOUS SYSTEM.

Nervous control of bodily functions: affected through disease of nerve
centres or nerve trunks, sensory, motor, vaso-motor, etc. Modes of
impaired nervous function: objective; subjective. Nervous
characteristics in different breeds, individuals, sexes, castrated
animals. Nervous disorder from microbian toxins, narcotics, nervous
stimulants, etc.

All bodily functions are more or less directly controlled by the nervous system, hence nervous troubles are interwoven with the diseases of all other organs. Disorder of the nerve centres or nerve trunks affects the most distant parts over which these preside, or to and from which they convey nervous impulse. In different cases we see this operating through the sensory or motor functions, through lack of coördination or of balance, through modification of the circulation, respiration, secretion, absorption, nutrition, metabolism, special sensation, intellection, emotion, etc. These manifestations are less evident or less diagnostic in the lower animal, because we cannot fully avail of the subjective symptoms. While the human patient can tell us his feelings and experience in their regular order and succession, we can only infer most of these in the animal, through dependent objective symptoms. In many cases we cannot even infer for lack of these dependent symptoms.

The practitioner must carefully watch for and accurately observe all objective symptoms, and seek to rightly interpret them. Among other things he must note the nervous conformation, organization and susceptibility; the hereditary nervous characteristics as seen in breeds, temperament, habit, aptitude to learn, docility, instinct, intelligence, emotions and affections, and judge the case in the light of these. Similarly he must take into account the hereditary, racial and individual irritability, obstinacy, restiveness, vice, alertness, sluggishness, stupidity, moroseness, and diagnose accordingly. Congestion, anæmia, coma, paresis, paralysis, may result from the nervous disorder and offer valuable concurrent testimony to the same. Allowance must always be made for the _use_ to which the animal has been put, thus _sexuality_ tells strongly in the horse, bull, boar, or ram which has been used for breeding and has become relatively indocile and even dangerous; _food_ tells in the horse that “shows his corn”, and in the dog fed on flesh; the comparatively untrained English race horse is far less docile than the one inured to saddle or harness and the horse fresh from the range, though previously trained, is far less tractable than the one in steady work. The _sexual products_ are especially liable to modify the temper, hence the docility of the gelding, and castrated mare, and the undisturbed life and steady growth and fattening of castrated animals from cattle to capons.

_The products of certain diseases_ and many _drugs_ derange the innervation and intellection. Of this we have examples in the hebetude of the victims of milk sickness and dourine, in the wild delirium of rabies, in the varied nervous disorders that attend on the use of narcotics, essential oils, alcohol, chloral, sulphonal, trional, strychnia, lead, phosphorus, arsenic, etc.

GENERAL SYMPTOMATOLOGY AND DIAGNOSIS.

Motor disorders: paralysis, paresis, hemiplegia, crossed hemiplegia,
spinal hemiplegia, paraplegia, monoplegia, local palsy,
pseudo-paralysis, spasm,—tonic,—clonic, tremor, hemispasm, monospasm,
spasm of eyeball, spasm of head, paraplegic spasm, general
spasms—convulsions, local spasms. Incoördination. Staggering. Reflex
action. Morbid reflex: increased reflex, reflex tonic spasm.

It seems desirable to note specially some of the more prominent morbid nervous phenomena and conditions, with lesions or other conditions which cause them, before considering what are usually recognized as special diseases.

MOTOR DISORDERS.

=Paralysis= (_Akinesis_) is loss of voluntary or involuntary muscular movement through defective innervation.

=Paresis= is a paralysis which is partial in degree; power of motion is impaired but not completely lost.

=Hemiplegia= is the loss of voluntary motion in many muscles on one side of the face or body. In general hemiplegia, the following muscles are usually excepted: muscles of the tongue, of mastication, of the eye, of respiration, of the neck and trunk, generally and of the proximal part of the limbs. The hind limbs are usually most affected, and muscles that are most exclusively under the control of the will those dominated by the cortical centres of the brain. When due to a clot on the brain or degeneration it occurs on the side opposite to that occupied by the clot, on account of the motor fibres crossing at the anterior pyramids of the medulla. Hemianæsthesia is a rare attendant and when present is often on the side opposite to the hemiplegia. Sensory fibres cross in the spinal cord, and the lesion is probably spinal.

=Crossed Hemiplegia= is motor paralysis of certain cephalic nerves (3d, 7th, 5th, 6th, and 8th,) on the same side with the clot or lesion, and of the muscles of the trunk on the other side. The cranial nerves proceed to muscles on the same side as their origin, while filaments going to the trunk through the spinal cord, cross in the pyramids (motor), or spinal cord (sensory). In crossed hemiplegia, hemianæsthesia is common with both forms of paralysis on one side.

=Spinal Hemiplegia= has the face and head sound (except sometimes the iris), and half the body paralyzed on the side opposite to that on which the spinal lesion (clot) exists. If anæsthesia exists it is on the side opposite to the lesion and posterior to it—the sensory filaments crossing just before leaving the cord.

=Paraplegia= is loss of voluntary power of one transverse half of the body; usually the posterior, and affects the tail, and has coincident anæsthesia, being due to a spinal lesion. Anal and vesical sphincters may or may not be paralyzed according as the lesions implicate their respective spinal centres or not. If there is neither anæsthesia nor vesical paralysis the lesion may be cerebral, in the paracentral lobes of both hemispheres (meso-vertix at the fissure of Rolando).

=Monoplegia= is a circumscribed paralysis, as of one limb, or on one side of the face, one group of muscles or a single muscle. It may be due to cerebral, spinal or nervous lesion. _Cerebral monoplegias_ are distinguished by: 1st, initial spasm; 2nd, absence of anæsthesia; 3d, persistence of nutrition; 4th, paralysis greatest in the distal portion of the member.

=Localized Paralysis= is usually due to lesion of a nerve, and is both motor and sensory. If due to a spinal lesion it usually affects one or more groups of muscles. In case the lesion is in the nerve, be guided, in investigating it, by Van der Kolk’s law, that the sensory fibres are usually distributed in the skin corresponding to the muscles which receive the motor fibres.

=Pseudo-paralysis= occurs from muscular disease, injury, inflammation or degeneration and has no appreciable central nor nervous lesion nor anæsthesia.

=Spasm= (_Hyperkinesis_); abnormal violent muscular contractions with or without loss of consciousness.

=Tonic= (_tetanic_) =Spasm= is violent and continuous.

=Clonic Spasm= is rapidly intermittent:—Contractions and relaxations.

=Tremor= (_trembling_) consists in small, intermittent, involuntary contractions.

=Hemispasm= affects the face, or limbs, or both, on one side of the body and may precede hemiplegia.

=Monospasm= affects one limb, one group of muscles or a single muscle. It may be due to lesion of the brain, of the spinal cord or of the nerves. Thus it may imply commencing disease of the motor centres or tracts.

=Spasms of the Eyeballs= (rolling of globe to one side), and =Spasms of the Eyeballs and Head=, are important indications of apoplexy. They imply disorder (commencing irritation) of the cerebral motor areas. Advanced disease would probably determine hebetude, coma, drowsiness, or palsy. If epileptiform it turns away from the lesion. If hemiplegic it turns toward the lesion and away from the paralysis. If lesion of the pons it turns away from the lesion.

=Paraplegic Spasm= is a tonic spasm, partial in degree, causing stiff, tetanoid (spastic) walk. In all four extremities there may be mixed paresis and contraction. This often attends on hemorrhage into the meninges.

=General Spasms=, convulsions as in Eclampsia, Epilepsy, Chorea, Tetanus.

=Local Spasms= may be rhythmic or not, in slight cases to be seen only in the eyelids or superficial muscles as twitching, and occur in neurasthenia, or in poisoning by strychnia, brucia and other motor nerve poisons.

=Incoördination= (_Dyskinesis_) is the lack of the harmonious balanced movement of the various groups of muscles. Coördination of movement is due to a special mechanism in the spinal cord, and extending forward through the medulla oblongata, pons, and crura cerebri to the floor of the third ventricle. In the form of _ataxia_ (lack of power of muscular control) it is usually the result of degeneration (sclerosis) of the superior columns of the cord, of the medulla, pons or crura. It may occur from degeneration or destructive change in the cerebellum, or from disease or section of the posterior roots of spinal nerves, or finally from the action of certain narcotic poisons (ptomaines, toxins).

=Staggering= (_titubation_) occurs from lesions of the cerebellum, medulla or pons; also from alcohol, opium, and other narcotics.

=Reflex Action.= The normal stimulation of different functions, motor, secretory, circulatory, etc., depends on the nerve centres in the spinal cord, which are roused into action by a centripetal impulse derived from a distant part. Thus the balanced contraction of the different muscles which preserves the equilibrium of the body, depends on the apprehension by the nerve centres, consciously or subconsciously, of such contractions (muscular sense), and it is largely under the control of the will. Here three impulses act coördinately: 1st, the afferent impulse from the muscle to the nerve centre; 2d, the efferent impulse from the nerve centre to the muscle; and 3d, the inhibitory or controlling, voluntary impulse from the sensorium to the nerve centre involved. In another case, savory odors, sapid flavors and masticatory movements cause a free secretion from the salivary glands. Again, the scratching of a dog’s breast causes him to move his hind limb as if he were himself doing the scratching. Again, the pricking of a limb causes the prompt, even if involuntary, contraction of its muscles to withdraw it from the source of irritation.

=Morbid Reflex.= Reflex action may be modified in various ways as the result of disease or injury. It may become excessive from irritability of the organ from which the centripetal impulse starts, or of the reflex centre in the spinal cord, or of the muscle or other organ to which the centrifugal impulse is directed, or, finally, from impairment of, or separation from the inhibitory centre in the cerebrum. It may be impaired or abolished from degeneration or destruction of any of the tissues just named, or of the conducting nerves which connect them to each other.

The contraction and closure of the pupil under light is a reflex act from the retina on the optic lobes, etc., and from these through the motor oculi to the iris. This reflex is lost and the iris fails to contract in: anæsthesia of the retina; atrophy of the optic nerve; disease of the optic lobe; superior (posterior) spinal sclerosis; disease of the motor oculi; or disease of the iris.

The lumbar reflex is lost in many febrile states in the horse, so that pinching of the loins fails to produce wincing, and this becomes a test of the active persistence of the disorder.

=Encreased Reflex= is often noticed when the parts, including the spinal reflex centre, are disconnected from the brain: as in lesions or disease of the cord in front (cephalad) of its reflex centre. Here the cerebral or voluntary inhibition is lost.

=Reflex Tonic Spasm= of muscles around a diseased or dislocated joint, or of those controlling its action, often affords a valuable means of diagnosis, the possibility of nervous, muscular and tendinous disease being excluded.

TROPHIC SYMPTOMS AND DISORDERS.

Degenerative atrophy, in hæmoglobinuria, laryngeal hemiplegia,
neurectomy, nerve lesion, brain or cord lesion, lead poisoning,
disuse. Dermatitis, ulceration, morbid secretion, polyuria,
mellituria, albuminuria, poisonous milk.

=Degenerative Atrophy=. From section, disease, atrophy or degeneration of nerves or nerve centres, the muscles, which they normally innervate, waste, often to an extreme degree. As examples of this we see the atrophy of the triceps extensor cruris and other groups in hæmoglobinuria, of the intrinsic laryngeal muscles in _roaring_, of the muscles supplied in neurectomy, and of groups of muscles in myelitis, broken back, lead paralysis, and scapular muscular atrophy. True to the law of wasting of physiologically inert organs, the nerves are atrophied and degenerated, and often also the bones, joints and skin.

The degeneration of an active organ applies to the nervous tissues themselves. According to the law of Waller, the nerve fibre (axis cylinder), when cut off from its nutritive centre (cell body with nucleus) degenerates and ultimately perishes. The axis cylinder is a component part of the neuron, which includes also its continuation in the cell and nucleus, and when the latter, which is the source and origin of both nerve impulse and trophic control, is lost, the inactive axis of the nerve fibre degenerates. This law is now availed of in tracing the distribution of nerve filaments, the degeneration being found in those that have been cut off from their nerve cells while those that come into the nerve trunk from other sources, distal of the injury, maintain their integrity.

In addition to this peripheral atrophy, a degeneration central of the injury to the nerve is seen under certain conditions, but especially in intrauterine life. In such cases the atrophy may extend up to and include the central nerve cells, causing a secondary central nervous lesion from an initial peripheral one.

By bearing these laws of nerve atrophy in mind, lesions that would otherwise be obscure, may be satisfactorily accounted for.

=Eruptions and Ulcerations of Nervous Origin.= Herpes or shingles in man is now recognized as a nervous disease, circumscribed to the distribution of given nerves and occurring unilaterally or bilaterally. Deep-seated dermatitis, vesicles, neuralgia, pain, itching and formication are common accompaniments. The whole is traced to disease of the ganglion on the posterior (superior) root of the spinal nerve distributed to the part. This establishes a principle, and in inscrutable and obstinate, circumscribed skin disease the veterinarian should see if it coincides with the distribution of one or more sensory spinal nerves.

_Ulcerations_ are often caused by the lack of protection of a part after paralysis, thus perforation of the cornea will follow section or disease of the trigeminus. These may be prevented by carefully covering the part, and even cured by a fine protective covering like collodion.

=Alteration of the Secretions= often follow on section of the sympathetic trunks, that of the cervical sympathetic in rabbits causing excessive congestion of the facial skin, with exudation and scabby product, also profuse secretion of sweat, tears, and ear cerumen and dry, scaly skin.

=Polyuria= is determined by section of one point of the medulla behind the root of the vagus, _mellituria_ by puncture between the vagus and auditory nerves (the hepatic vaso-motor centre), and _albuminuria_ by a puncture in front of the latter. Impairment of the hepatic vaso-motor tracts in the spinal cord, or of the anterior or posterior cervical sympathetic ganglia, or of the first thoracic ganglion equally determines nervous mellituria.

=Poisonous milk= produced in hard worked mares, or over-excited dams of other species, causing dyspepsia, diarrhœa, arthritis or other trouble in the suckling, must be in part attributed to nervous disorder.

Practically all secretions and nutrition are largely under nervous control, so that modifications in quantity or quality can often be attributed to nervous influence.

SENSORY SYMPTOMS AND DISORDERS.

Hyperæsthesia, cutaneous, thermic, muscular, visceral. Paræsthesia,
pressure on nerve. Anæsthesia, partial, drug. Analgesia. Hyperalgesia.

These are necessarily much less obvious to the veterinarian than to the physician of man. Yet in certain cases they may be observed directly, and in others deduced from dependent symptoms.

=Hyperæsthesia= is a state of exalted excitability of any part of the sensory nervous apparatus.

=Cutaneous hyperæsthesia= is that condition in which the slightest touch gives rise to an instant and extreme response. Some nervously organized mares which are dangerously ticklish and irritable, afford physiological examples. The surface soreness and sensitiveness which exist in the febrile chill, in wounds, dermatitis and neuralgia give pathological examples. It is further seen in certain cases of meningitis (cerebral and spinal), spinal irritations, rabies, tetanus and neuritis.

=Hyperæsthesia to cold= is seen in neuralgia, rheumatism, the early stages of many fevers (chill), in myelitis, neuritis, nerve injuries, and in posterior (superior) spinal sclerosis.

=Hyperæsthesia of the muscles= may be noted in tetanus, muscular rheumatism and neuralgia.

_Visceral hyperæsthesia_ is shown in many cases of spasms of involuntary muscles (colic, arrest of intestinal calculi, gall stones or urinary concretions), and in inflammation of serous membranes (pleurisy, peritonitis).

=Paræsthesia.= This is a painful or morbid sensation caused by a lesion in the central nervous structures or in the nerves, but referred by the sufferer to some peripheral organ over which such centre presides. It may even be referred to an organ or part that has been amputated or otherwise removed. This may cause lameness of a kind to indicate suffering in a given muscle, tendon or joint, when the cause is purely central. In dourine, sexual acts are excited which have their real source in the nerve centres. The rabid dog snaps at imaginary flies in mid-winter, when such insects are only phantoms of his brain.

=Pressure on a nerve trunk= induces sensations of tingling, vibration, formication, heat, cold, and paresis, referred by the mind to the part to which that nerve is distributed, and when the pressure is removed these sensations recede in the order in which they came. This may explain some occult cases of lameness.

=Itching= may be a pure, persistent neurosis without any skin lesion. Treatment should then be addressed to the nervous system.

=Anæsthesia=, or absence of sensation, is in its degree partial or complete. The latter is familiar as occurring in parts the sensory nerves of which have been cut across, also in parts the sensory nerve or nerve centres of which have become completely degenerated. There is no response to the prick of a needle, the touch of a hot wire, to pinching or cutting. If the nerve remains intact as far as the spinal centres, reflex action may still occur, but the patient himself has no consciousness of this nor of the injury causing it. Accordingly, he makes no movement of head, ears, eyes, or other parts still dominated by the brain.

In =partial or imperfect anæsthesia= the response to irritation is less marked and may be even delayed. In some forms of central lesions the response to a prick may be delayed two, five, or ten seconds, or even more.

_Anæsthesia_ causes awkwardness or uncertainty of movement, especially if the subject is blindfolded.

_Anæsthesia_ may be =induced by medicine=, as in the general anæsthesia of etherisation, or the local anæsthesia caused by the topical application of cocaine or carbolic acid.

=Analgesia=, or insensibility to pain, may be present in cases in which ordinary sensations are still felt. It may be caused by cocaine, alcohol, and to some extent by carbolic acid.

=Hyperalgesia= is the opposite of this condition, and may be seen in certain irritable conditions of the nerve centres.

PSYCHIC SYMPTOMS AND DISORDERS.

Limitation in lower animals. Effects of age training, race heredity,
individual and racial peculiarities, exhaustion, prostration,
dementia, cerebral congestion, compression, degeneration, narcotics,
ptomaines, toxins. Controlling absorption in another trouble.
Delusions, hallucinations, vice, violence, œstrum, fatigue. Cerebral
source of motions.

These have a much more restricted field in the lower animals than in man in keeping with the limitation of the mental faculties, and they may often be traced to demonstrated structural disorder. Yet some emotions of joy, fear or rage run very high and are comparatively unchecked by high mental development or mental training. The effect of training is, however, very marked in the more educated animals.

=Age= modifies by the sobering that comes from experience and habit. The frolics of puppies, kittens, lambs, foals and calves are in marked contrast with the sedateness and stolidity of old dogs, cats, sheep or cattle.

=Training= is seen in the educated horse which would have been panic stricken at sight of a locomotive, flag or floating paper, at the smell of a lion or bear, at the sound of a gun or drum, and which will now boldly face any one of these with no manifest tremor. The emotional puppy can be trained to soberly fetch and carry, to drive sheep or cattle without biting, to lie sentinel by his master’s property, to point at birds without seeking to catch them, or to carry shot birds without devouring them.

=Race heredity= comes from the training along the same lines in many successive generations. Thus the more domesticated breeds of dogs (shepherd, poodle, and greyhound) are very affectionate; other breeds (bull, mastiff, bloodhound) are lacking in this character. All trained races take naturally to the occupations of their ancestors. Some (horses, cattle and sheep) are easily panic-stricken, (stampeded). Some (turkeys, roosters) are not easily stampeded. Some (skunks), having effective sources, of defence, have little fear of man.

=Individual and racial mental dullness and torpor= must also be recognized. Some are stupid and slow, others alert and quickly responsive. Some horses are not _level-headed_ and become uncontrollable in difficult situations. Some dogs are so emotional as to endanger their lives from sudden heart trouble. Some horses, dogs and cats will pine and die when separated from their fellows or human friends. Extreme timidity, or sudden rage may be so marked as to constitute a virtual morbid phenomenon. Sluggish cerebral and mental action may result from _exhaustion_, _prostration_, or _dementia_; also from _cerebral congestion_, _pressure_ and _degeneration_; or from _poisoning by narcotics_, _ptomaines_ or _toxins_ (opium, hyoscyamus, Indian hemp, dourine, milk sickness, etc.). It may come from profound absorption in another object, as when the rabid dog bears whipping without a howl.

=Delusions= or =hallucinations= are shown in the rabid dog snapping at flies, or attacking his friend or master as an enemy, as well as in other forms of delirium. Narcotics, such as opium, Indian hemp, etc., ptomaines, toxins, and (in dogs) essential oils cause delirium by acting on the nerve centres.

=Vice= in its various forms may become a genuine neurosis, the animal losing control of its actions.

=Violence= in the form of self-defence or aggression is seen in mares in _heat_, in bulls or stallions under sexual excitement, in animals roused by inconsiderate whipping, or in bulls looking on scarlet clothing.

Some high-spirited animals, under extreme fatigue from overwork, sometimes become violent but resume their docility under rest and food.

In all cases we must know the normal of an individual animal to enable us to properly appreciate any apparent deviation from the psychic norm. No less essential is it to take into account the environment and treatment of the patient.

With regard to localization of cerebral lesions, Sequin thinks emotions are probably generated in the basal ganglia such as those of the pons and thalami, while inhibition depends on the anterior cerebral cortical convolutions.

DIAGNOSIS, SYMPTOMS AND THEIR IMMEDIATE CAUSES. LOCALIZATION OF LESION
IN SPECIAL SYMPTOMS.

Spasm, pain, numbness—irritation. Paresis, paralysis, anæsthesia
(constant)—destructive lesions. Both combined—variable symptoms,
recurrent. Definite, fixed symptoms—structural lesions, usually
progressive. Symptoms, variable as to place, time, subsidence and
recurrence—functional lesions. Brain lesions. Pressure on brain—pain,
spasm, nausea, dullness, blindness, stupor, coma, palsy. Congestion
and anæmia synchronous. Lesions of cortex. Encephalic
lesions—hemiplegia, with spasms, increased reflexes, spasms follow
cranial nerves, vertigo, apoplexy, epilepsy, dementia, coma, little
muscular atrophy, or dermal sloughing. Spinal lesions, paraplegia
without spasm, reflex reduced or nil, follow spinal nerves, head
symptoms less, much muscular atrophy, bed sores. Sensory and motor
tracts, in crus cerebri, respiratory centres—inspiratory expiratory,
inhibition. Salivation, sneezing, coughing, sucking, chewing,
swallowing, vomiting. Cardiac centres, accelerating and inhibitory.
Vaso-motor centre. Spasm centre. Perspiratory centre. Pons. Corpora
quadrigemini, crura cerebri. Thalamus, corpus striatum. Cerebellum.
Cerebral cortex: in ass; in dog. Spinal lesions: lateral half section:
central anteroposterior, vertical section: superior columns: inferior
columns: cervical lateral columns: respiratory tract: glycogenic
centre: pupillary dilator: cardiac accelerator; vaso-motor,
sudoriparous: centre for anal sphincter: for vesical sphincter:
genital centre: vaso-motor and trophic centres: muscular sense tract:
superior column and Goll’s. Table of phenomena from cord lesions.

In =Irritation= of nervous organs the symptoms (spasm, pain, numbness) are usually _intermittent_.

In =Destructive Lesions= of nervous organs the symptoms (paresis, paralysis, anæsthesia) are usually _constant_.

When =irritation and destruction= are associated the symptoms are variable and frequent. The characteristic symptoms of the two may coexist or succeed each other.

=Structural Nervous Lesions= have symptoms that are definite in their area of distribution, nature (spasm, paralysis) and permanency. _Objective Symptoms_ predominate and the case is likely to be progressive and fatal.

=Functional Nervous Diseases= have symptoms of indefinite distribution, variable in character, with intermissions and spontaneous disappearances (as under marked excitement) and subjective symptoms predominate. They may, however, last for a length of time without change.

Localisation of Brain Lesions.

Lesions of the cranial nerves and their superficial and deep centres of origin need not here occupy attention. These may be studied in works on anatomy and physiology. Attention may be drawn rather to the remoter effects of ganglia which affect or control distant action, and to general pressure on the encephalon.

=General Pressure on the Encephalon=, whether through fracture of the cranium and depression of bone, by acute congestion, by blood extravasation, by inflammatory exudation, or by acute abscess, will cause pain, spasms, nausea, dullness, blindness, stupor and coma. After expulsion of the cerebro-spinal fluid from the cranial cavity, the increasing pressure compresses the blood vessels, reduces or interrupts the circulation and abolishes the functions in the parts deprived of blood. Thus congestion of one portion of the encephalon is usually associated with diminished circulation in another portion. Disorder in the first may occur from hyperæmia and irritation and in another part from a consequent anæmia.

=Destructive Lesions of Cortex of One Cerebral Hemisphere= may or may not cause permanent symptoms, as shown by the passage of a crowbar through the front of the left hemisphere, yet the man survived for 13 years and showed no loss of intelligence, his disposition and character alone having changed for the worse. The one hemisphere may by itself sufficiently control mental acts, while the other lies dormant or may even have undergone degeneration.

=Diagnosis of Encephalic and Spinal Lesions.= The following may be taken as guiding principles:

=Encephalic=: Hemiplegic or bilaterally hemiplegic grouping of symptoms.

=Spinal=: Paraplegic grouping of symptoms.

=Encephalic=: Frequent contracture or spasms of paretic muscles.

=Spinal=: Paralysis more perfect and continuous.

=Encephalic=: Reflexes in affected muscles increased: Cerebral inhibition absent.

=Spinal=: Reflex abolished or reduced in parts the seat of the lesion.

=Encephalic=: Spasms in areas of distribution of cranial nerves (not spinal.)

=Spinal=: Spasms and paralysis follow distribution of spinal nerves.

=Encephalic=: Head symptoms frequent (vertigo, apoplexy, epilepsy, dementia, coma).

=Spinal=: Relative absence of head symptoms.

=Encephalic=: Comparative absence of marked muscle atrophy.

=Spinal=: Atrophy in special muscular groups.

=Encephalic=: Little tendency to form bed sores.

=Spinal=: Tendency to form sloughs and bed sores.

Sensory (Æsthesodic) and Motor (Kinesodic) Tracts in Encephalon.

In the crus and above, the sensory tract lies dorso-laterad of the motor tract, forming about one-fifth of the crus, and extending upward through a white layer bending inward to form an angle and finally diverging to the different cortical convolutions. The motor tract is mainly contained in the inferior pyramids of the bulb, and constitutes the median two fifths and basal two fifths of the crus. Without entering farther into this subject it will be observed that lesions of the outer layer of the crus and its radiating fibres may cause hemianæsthesia of body or head, including the eye, while lesions of the median and basal layers and radiating fibres induce hemiplegia of the head, tongue, fore limb, hind limb, trunk, etc.

=Respiratory Centres, Inspiratory and Expiratory= are in the floor of the fourth ventricle between the centres for the vagus and accessory nerves, and are directly stimulated by the CO_{2} in the blood. Secondary subsidiary centres are in the optic thalamus, in the corpora quadrigemini both anterior and posterior pairs, and finally in the cervical spinal cord, so that disorder of respiration may occur from lesions in these points as well as in the main oblongata centre.

=Respiratory Inhibition= and arrest depend on the vagus, the superior and inferior laryngeal nerves.

=The Salivation Centre= also lies in the floor of the fourth ventricle and stimulation of the medulla causes free secretion.

=The Centres for Sneezing, Coughing, Sucking, Chewing, Swallowing and Vomiting= are also seated in the oblongata, so that any one of these phenomena may come from a central irritation. In _bulbar paralysis_ the loss of power usually extends from the tongue through the lips, cheeks, jaws, pharynx, larynx, to the respiratory muscles and heart. Coughing may be roused by irritation of the external auditory meatus, liver, stomach, bowels, or generative organs as well as from the air passages.

=Cardiac Accelerating and Inhibiting Centres= are both present in the bulb, the latter receiving its afferent impulse mainly through the vagus nerve. Stimulation of the vagi, anæmia of the bulb through decapitation or through tying both carotids, hyperæmia through tying of the jugulars, a venous state of the blood, and blows on the abdomen all slow or arrest the heart action. Digitalis or muscarin has a similar effect. The heart action is accelerated by febrile and inflammatory affections, by a high or low temperature by section of the vagi, by sipping of cold water, by atropine or curari, and by salts of soda. Potash salts on the other hand restore the inhibitory action of the vagi and lower the heart’s action.

=The Vaso-Motor Center= is also in the oblongata and the contraction of the vessels with increase of arterial pressure may ensue from afferent currents in the sympathetic nerve and many sensory trunks. The varying activity is seen in blushing, in the congestion of mucous membranes under rage or excitement, in the capillary contraction in the early stage of inflammation, in the second stage of capillary dilation, in angioma or nævus and in extensive congestions and hæmorrhages in different organs. The arrest of bleeding under fainting is due largely to the anæmia of this centre.

=A Spasm Centre= the pricking of which causes general convulsions lies in the medulla oblongata at its junction with the pons. This is excited by excess of carbon dioxide in the blood, by suffocation, drowning, by anæmia of the bulb from bleeding or ligature of the carotids, by venous congestion after ligature of the jugulars, or by the direct application to the part of ammonia carbonate, or salts of potash or soda. It may also be roused by afferent nervous currents from different peripheral parts (spinal cord, sciatic nerve, etc.).

=A Perspiratory Centre= is found in the medulla, on each side, which may be roused into action by diaphoretics (opium, ipecacuan, tartar emetic, Calabar bean, nicotin, picrotoxin, camphor, pilocarpin, ammonia acetate, etc.).

=The Pons= like the medulla is at once a ganglionic and conducting organ, and its lesions may lead to arrest of nerve currents generated above or below it, or to the failure to develop currents in its own centres. Stimulation of its superficial layers may be without effect, but if this is carried into the centre epileptiform convulsions ensue. Lesions of one side of its posterior half cause facial paralysis on the same side and motor and sensory paralysis on the opposite side of the body (crossed hemiplegia). Lesions of one side of its anterior half cause paralysis in both face and body on the same side. This depends on the crossing of the fibres midway back in the pons, which cross again in the medulla (motor fibres) and in the spinal cord (sensory fibres). Lesions of the pons are liable to interfere with the functions of the trigemini, the oculo motor and the superior oblique, and to determine epileptic movements and loss of coördination of sensorio-motor movements. Lesions of the superficial transverse fibres (median cerebellar peduncles) tend to cause involuntary movements to one side.

=Lesions of the Corpora Quadrigemina= cause disturbance of vision, failure of the pupil to contract to light, blindness, paralysis of the oculo-motor nerves, and lack of coördination of movements. Stimulation of one anterior corpus causes rolling of both eyes to the opposite side, with, if continued, a similar movement of the head and even of the body (horse in mill, or index motion, or rolling on its axis).

=The Crura Cerebri= are conducting bodies but contain also different nerve centres. Lesions of one crus cause violent pain and spasm on the opposite side of the body, followed by paralysis. The oculo motor may be paralyzed on the same side, but the face and tongue on the opposite side, owing to the fibres crossing in the pons. There may be turning movements.

=The Optic Thalamus= transmits sensory currents to the cerebral cortex. Lesions in this organ cause sensory paralysis on the opposite side of the body. Afferent currents that do not traverse the thalamus cause reflexes only. It contains one of the roots of the optic nerve and its destruction will impair vision. Its injuries may also produce turning movements.

=The Corpus Striatum= transmits motor currents originating in the cerebral cortex. Lesions of its interior (lenticular nucleus) cause motor paralysis and sometimes anæsthesia on the opposite side of the body. Electrical stimulation of this nucleus causes general muscular contractions of the opposite side of the body. Irritation of the surface layers is painless and symptomless.

=The Cerebellum= has been long credited with coördination, and Flourens, after its removal from a pigeon, found an utter lack of harmonized movement in walking, springing or balancing. Luciani removed the organ from a bitch and, after full healing of the part, found a lack of muscular tone (a cerebellar ataxy), so that no great muscular effort could be satisfactorily accomplished. After months, marasmus set in and proved fatal. The lack of coördination is especially connected with lesions of the vermiform process, those of the posterior portion causing falling forward and those of the anterior portion, falling backward. Injury to the middle peduncle on one side causes turning or rolling to the opposite side. Under slighter injuries there may be only unsteadiness and staggering like a drunken man. Nausea and vomiting, with more or less stiffness of the neck or oposthotonos, may be present. Rolling of the eyes or squinting may occur.

=Focal Cortical Centers of the Cerebrum. Cortical Localization.= Much has been done experimentally and by observation of morbid lesions to locate functions in the different convolutions, and though the subsidiary implication of adjacent and interdependent parts interferes with a perfectly confident diagnosis, yet certain fundamental facts may be borne in mind as contributing to a satisfactory diagnosis.

Arloing, on the basis of his own experiments and those of his predecessors, gives the following as applicable to the equine (ass) brain:

1. Stimulation of the origin of the front part of the first frontal convolution, or of the anterior part of the pre-Sylvian convolution, causes approximation of the feet on the opposite side of the body.

2. Stimulation of the superior part of the first frontal convolution or of the superior part of the post-Rolandic convolution causes closure of the jaws and diduction.

3. Stimulation of the anterior end of the upper orbital convolution, or of the anterior part of the pre-Rolandic convolution, leads to movements of the nose and upper lip.

4. Stimulation of the antero-superior part of the lower frontal convolution, or the union of the post-Rolandic with the Sylvian convolution causes movement of tongue and jaws.

5. Stimulation of the union of the vertical and horizontal parts of the orbital convolution or frontal lobe, causes opening of the jaws and bending of head and neck.

6. Stimulation in the front of the union of the frontal and longitudinal convolutions, or at the union of the Sylvian and second parietal convolution causes rolling of the opposite eye.

7. Stimulation of union of the frontal and parietal parts of second parietal convolution leads to closure of both eyelids or, with a strong current, of lids on both sides.

8. Stimulation of the second parietal convolution, above and a little behind the extremity of the Sylvian fissure, causes opening of the eye and adduction of the ear on the opposite side, or, if a very strong current, on both sides.

9. Strong stimulation of the posterior part of the first and second parietal convolutions causes tonic convulsions.

10. Currents through the posterior parts of the third and fourth parietal convolutions gives similar convulsions with violent trembling of the trunk and members.

In the =Dog’s Brain= localization is easily made by reference to the crucial fissure which passes outward, right and left, at right angles with the longitudinal fissure about the junction of its anterior with its middle third. Also by four parietal convolutions which run backward from near the crucial fissure, parallel with the longitudinal fissure. They are counted from without inward. Fritsch, Hitzig and Ferrier have mapped out the following motor areas:

1. The convolution in front of the outer end of the crucial sulcus controls the muscles of the neck.

2. The bend of the same convolution backward, opposite the outer extremity of the crucial sulcus, controls the extensors and adductors of the fore limb.

3. The convolution just behind the outer end of the crucial sulcus controls the muscles which flex and rotate the fore limb.

4. The same convolution behind the middle of the crucial fissure controls the movements of the hind limb.

5. The second convolution back of the crucial fissure controls the muscles of the face.

6. The anterior part of the internal (4th) parietal convolution, just back of the crucial fissure, controls the lateral switching movements of the tail.

7. The posterior angle of the first post-crucial convolution causes retraction and abduction of the fore limb.

8. The outer end of the first post-crucial convolution, directly behind the outer end of the sulcus, causes raising of the shoulder and extension of the fore limb.

9. The anterior end of the third parietal convolution (the second from the longitudinal fissure) controls closure of the eyelids, the rolling of the eyeball upward, and narrowing of the pupil.

10. Stimulation of the anterior end of the second parietal convolution causes partial opening of the mouth with retraction and elevation of its angle.

11. Stimulation of the point of union of the first and second parietal convolutions anteriorly causes opening of the mouth with protrusion and retraction of the tongue.

12. Stimulation of the median part of the second parietal convolution, causes retraction and elevation of the angle of the mouth.

13. Stimulation of the convolution directly in front of the outer end of the crucial sulcus causes dilatation of the eyelids and pupil while the eyes and head are turned toward the opposite side.

14. Stimulation of the convolution behind the crucial fissure causes contraction of the muscles of the perineum.

15. Stimulation of the convolution in front of the crucial fissure, on its anterior and sloping portion, causes movements of the pharynx and larynx (swallowing).

16. Stimulation of motor areas of the cortex, by scraping, irritation, or disease tends to produce spasmodic contractions of certain groups of muscles (Jacksonian Epilepsy). Strong stimulation may cause general epileptiform spasms, which are at first tonic, then clonic. One such seizure strongly predisposes to a second. If, during an attack, the cortical centres presiding over a special group of muscles were sliced off, such muscles relaxed, though the general spasms in the other muscles continued.

Localizations of Spinal Lesions.

Being at once a conductor between the brain and nerves, and a reflex nerve centre, we must consider both rôles in seeking to locate lesions from symptoms. In passing from the nerves to and from the sensorium both sensory and motor currents cross so that one side of the brain presides over the other side of trunk and limbs. This crossing of the motor fibres takes place in the medulla oblongata, while that of the sensory fibres occurs in the spinal cord close in front of the nerve from which they have entered.

=Cross-Section of one lateral half of the spinal cord= therefore causes motor paralysis and rise of temperature of the whole of that side of the body posterior to the lesion, while it induces sensory paralysis and cooling on the opposite side of the body up to the same point. A very limited sensory paralysis on the same side occurs corresponding to the few sensory fibres passing outward obliquely through the portion injured by the cross-section.

=A vertical section of the cord separating the one lateral half from the other= does not necessarily affect the motor currents, while it produces a limited anæsthesia on each side in the area of distribution of the nerves, the sensory fibres of which crossed in the seat of the lesion.

=Transverse section of the superior columns= causes hyperæsthesia and lack of coördination.

=Transverse section of inferior columns=, or of the inferior horn of gray matter, if close behind the medulla, causes no motor paralysis, but if farther back induces motor paralysis on the same side of the body.

=Transverse section of the cervical lateral columns= causes motor paralysis of the lateral walls of the chest (respiratory tract). If the section is made in the dorsal or lumbar region it is the same as lesion of the superior columns.

Among =reflex centres= in the cord the following may be named:

The =Respiratory Tract= in the cervical lateral columns just referred to.

A =Glycogenic Centre= in the anterior cervical section between the bulb and the fourth cervical nerve.

=Centres which Dilate the Pupil= between the fifth cervical and the sixth dorsal nerve.

=Cardiac Accelerator Centres= between the three last cervical and the five first dorsal nerves.

=Vaso-Motor Sudoriparous Centres= in the central gray matter.

=Centre for Anal Sphincter= between the sixth and seventh dorsal nerves.

=Centre for Vesical Sphincter= between the third and fifth lumbar nerves.

=Genital Centre=, opposite the first lumbar nerve.

=Vaso-motor and Trophic Centres= are found in the inferior horns of gray matter, and their degeneration causes progressive muscular atrophy.

The =Muscular Sense Tract= is located near the surface of the superior columns, so that a certain amount of incoördination and unsteadiness of progression follows its destruction.

The =Deeper Part of the Superior Columns= and the =Column of Goll= which bounds the superior median fissure control muscular sense and coördination, and their disease (posterior lateral sclerosis) entails locomotor ataxy.

TABLE SHOWING PROMINENT PHENOMENA FROM LESIONS OF THE CORD.

─────────────────┬─────────────────────────────────────────────────────
│ LESIONS IN
─────────────────┼─────────────────┬─────────────────┬─────────────────
„ │Cervical Region. │ Dorsal Region. │ Lumbar Region.
─────────────────┼─────────────────┼─────────────────┼─────────────────
Paralysis in │Neck muscles; │Dorsal, abdominal│Paraplegia.
│ diaphragm; │ and intercostal│
│ trunk; limbs. │ muscles. │
│ │ Paraplegia. │
Sensation │Local │Hyperæsthesia in │Hyperæsthesia in
│ hyperæsthesia │ lower part of │ zone around
│ in fore limbs. │ abdominal wall.│ loins;
│ Anæsthesia in │ │ anæsthesia in
│ rest of limbs │ │ hind limbs.
│ and trunk. │ │
Atrophy │Rare in neck; │Slight in muscles│In hind limbs.
│ common in fore │ behind lesion. │
│ legs. │ │
Electric reaction│Lessened in │Lessened in │Lessened in
│ atrophied │ dorsal and │ atrophied
│ muscles. │ abdominal │ muscles; in
│ │ muscles: │ ratio.
│ │ slightly in │
│ │ wasted leg. │
Bladder │Retention or │Same as cervical.│Incontinence from
│ intermittent │ │ palsy of
│ incontinence │ │ sphincter.
│ reflex, or │ │
│ (later) from │ │
│ overflow. │ │
│ Cystitis │ │
│ common. │ │
Bowels │Involuntary │Same as cervical.│Paralysis of
│ evacuation │ │ sphincter with
│ (reflex spasm) │ │ incontinence;
│ or │ │ costiveness.
│ constipation. │ │
Superficial │Temporary loss; │Same as cervical.│Lost.
reflex │ then rapid │ │
│ increase. │ │
Deep reflex │Temporary loss; │Same as cervical.│Lost.
│ then slow │ │
│ increase. │ │
Priapism │Often present. │Often present. │Absent.
─────────────────┴─────────────────┴─────────────────┴─────────────────

HALLUCINATIONS.

Subjective cerebral impressions projected as real. Rabies. Toxins.
Poisons. Essential oils. Chloroform.

Hallucinations are subjective impressions which the animal supposes to be real. The disorders in his brain are projected outward and become to him real objects and occurrences.

They may arise from the presence and proliferation of microbes in the brain as in rabies in animals. They may proceed from poisoning of the brain by toxins as in anthrax.

They may be developed, in dogs especially, by the action of certain essential oils on the cerebral cortex. The first two classes will be considered with those special diseases. The mental disorders from drugs have been studied experimentally by Cadeac and Mennier, and may be noticed in this place.

Lavender, fennel and angelica produce in the dog a condition of extreme terror, and overcome all disposition to exercise self-defense.

Mints and origanum induce hallucinations of odor. The dog seeks around with head and nose elevated, sniffs the air, moves cautiously, fixes his eye on some phantom object, and starts to hunt imaginary game. The love of catmint seems to amount to a mania in the feline animal.

Kidney vetch evidently causes a sensation of itching or formication; the dog bites the hair of the tail, the hind limbs or the flank as if to destroy fleas or other vermin.

Dogs under chloroform have sought to hunt, and stallions under ether have shown generative excitement with erection of the penis and movements of coition.

TIMIDITY. PANIC. STAMPEDE.

Timidity. Panic. Timid driver. Impaired vision. Nervous. Irritability.
Gadding. Gregarious habit. Absence of natural weapons. Treatment.
Habit. Substitution. Absolute constraint. Kindness. Boldness. Work.
Moderate diet.