Reports of Societies. which he detailed the indications for the operation; THE ANNUAL MEETING OF THE PENNSYL-performed, with the report of an original case in which THIRD DAY'S PROCEEDINGS. PROFESSOR LEIDY, President of the Anatomical THE BICHLORIDE OF MERCURY AS A SURGICAL DRESSING, of amputation of breast and other major operations spoke enthusiastically in its praise, and reported cases which healed without a drop of pus. Board of the State (appointed under the law recently adopted to protect dissection by the distribution of cadavers from various public institutions throughout the State to the colleges), addressed the Society, and requested the coöperation of the medical profession of Pennsylvania in seeing the law faithfully and fairly the Committee upon Publication of papers and abstracts Upon reassembling in the afternoon the report of executed. AN ELECTRIC LARYNGOSCOPE was shown by DR. CARL SEILER, which consisted in a small arc-lamp fixed in front of the mirror on the forehead of the observer. It was operated by a storage battery. DR. J. SOLIS COHEN exhibited Trouvé's polyscope for examining the larynx, and for rhinoscopy. In a communication entitled Does Chronic Discharge from the Ear make Life Insurance Hazardous? DR. CHARLES L. TURNBULL answered the query in the affirmative, after considering the reports of a number of cases. DR. PETER D. KEYSER in a conclusion of the paper read at a former meeting, on Some Ophthalmological Observations during Ten Years' Service in Wills' Eye Hospital, gave a number of clinical histories of cases of affections of the choroid, retina, optic nerve, recti muscles, sclerotis, vitreous, etc., with some anomalies of refraction. THE ADDRESS IN SURGERY was delivered by DR. JOHN B. ROBERTS, of Philadelphia, who exposed some "surgical delusions" with regard to the safety of chloroform anæsthesia; the value of styptics, dangers of trephining the skull, necessary fatality of heart wounds, lateral symmetry of normal limbs in the same individual, and one or two other points of interest. DR. E. T. BRUEN read a paper upon the OPERATIVE TREATMENT OF PURULENT PLEURAL EFFUSIONS, PUBLICATION OF PAPERS AND ABSTRACTS. was presented as follows: this Society become thereby the exclusive property of "All the papers read or appointed to be read before the Society, and the author has no right to publish or cause to be published the paper or any part of the mittee on Publication shall not be at liberty to publish The Comsame without the consent of this Society. any paper that has been published in violation of the above requirements. "Resolved, That the Medical Society of the State of Pennsylvania look with great disfavor upon the making use of this organization as an advertising medium, violation of the spirit of the Code of Medical Ethics." and hold such practice as contemptible as a flagrant Society reserved the right to furnish abstracts or to This was adopted with the amendment that the permit them to be furnished for publication. DR. DE FORREST WILLARD read an excellent paper upon NON-NECESSITY OF TARSOTOMY IN TALIPES OF CHILDREN, and presented cases showing the value of manipulation and stretching with proper apparatus. He exhibited foot was attached to a belt around the pelvis by a vera form of apparatus in which a shoe on the affected tical, lateral steel rod, jointed opposite the knee and thigh, in connection with which was a long spiral spring, which by a constant action everted the toes. Cases were shown and photographs passed around to prove that tarsotomy is not needed in children even when the deformity is great. DR. A. SYDNEY ROBERTS exhibited several cases illustrating the application of a new form of splint to the treatment of Chronic Articular Osteitis of the Knee-Joint, and DR. W. S. JANNEY exhibited a case of deflection of the trachea, in which the presence of a large tumor of the neck had required the performance of tracheotomy. REPORTS, RESOLVES, AND ANNOUNCEMENTS. A favorable report on the plan submitted during the first day to found a society to organize a State Board of Health, and to help educate the community in medical matters and the principles of health was adopted without debate. Resolutions paying tributes to the memory of the late Professor Gross, and proposing the erection of a monument to him in Fairmount Park, were unanimously approved. The time for the next meeting, at Scranton, was written in conjunction with Dr. J. Wm. White, in changed from May 2, 1885, to the last Wednesday in May, on account of the proximity of the former date 1 Continued from page 535. to the time of the meeting of the American Medical Association in New Orleans. The announcements for the regular addresses in next year's session were made as follows: In surgery, Dr. E. A. Wood, of Pittsburg; in obstetrics, Dr. C. A. Rahter, of Harrisburg; in hygiene, Dr. J. G. Richardson, of Philadelphia; in mental diseases, Dr. S. S. Schultz, of Danville; in otology, Dr. C. S. Turnbull, of Philadelphia. Just previous to the adjournment sine die the new President, DR. E. J. ALLEN, was introduced by the ex-president, who made some valedictory remarks, and welcomed his successor, to which Dr. Allen responded in a few words, thanking the Society for the honor conferred. The Association then adjourned. PROCEEDINGS OF THE BOSTON SOCIETY FOR MEDICAL IMPROVEMENT. E. M. BUCKINGHAM, M. D., SECRETARY. sometimes in the mastoid cells, and not infrequently in other parts of the body, as the vagina. It might be that further investigation would show that collections like the one under discussion, consisting of a distinct roll of epidermis, were influenced to take the form of a roll by the dermoid movement, but even in these cases it seemed to him we must assume a pathological process to account for the enormous epithelial develop ment. DR. HOOPER, in answer to a question by Dr. Minot, said that the patient complained of deafness. Both ears were full of cerumen, and this compact mass was syringed out. The drum was much injected, yet there had been no history of inflammation. Hearing is now perfect. LINKS OF ARTICULATED CATHETER REMOVED FROM THE BLADDER. DR. J. COLLINS WARREN showed several links of an articulated metallic catheter, which had broken off in the bladder when passed by the patient, an accident which has happened several times. They had been MAY 26, 1884. The President, DR. CHARLES D. retained some six months, and he used the lithotrite, HOMANS, in the chair. SPECIMEN ILLUSTRATING PROGRESSIVE MOVEMENT OF DERMOID LINING OF EXTERNAL AUDITORY CANAL. DR. F. H. HOOPER showed a specimen which had been removed from the ear, and which came away sticking to a ceruminal plug. The specimen represented the dermoid coat of the membrana tympani and of a portion of the external auditory canal. When first syringed out it was rolled up into a compact mass, but on being placed in water it unravelled to its present length, which is four inches and a half. Its width is half an inch. The specimen illustrated very well the progressive movement from within outward of the dermoid lining of the external auditory canal and of the outer coat of the membrana tympani. This movement has long been recognized, and even the direcion with which it takes place has been demonstrated by Dr. C. J. Blake's ingenious observations on the subject. In this instance the epidermis in its outward movement, meeting with the resisting plug of cerumen, gradually folded up on itself (like the sides of an accordion when the instrument is closed); which explains how a mass of this length could be accommodated in the small portion of the meatus between the ceruminal plug and the drum-membrane. DR. J. ORNE GREEN said the specimen shown was an unusually large and perfect one. In regard to the mode of formation of these collections it would be interesting to know whether the roll lay across or lengthwise of the meatus, and he was not aware that this fact had been as yet noted; if the explanation given was the correct one, we should expect it to lie across. For himself he was unable to accept the undoubted outward growth of the dermoid layer of the drum-membrane as explanatory of all or even of the majority of these epidermal collections in the meatus; for such were often found on a circumscribed portion of the walls of the passage only, even in the extreme outer portions, all other parts of the walls and of the drum-membrane being healthy. He was rather inclined to refer them to what has been called "desquamative inflammation," which leads to large collections of epidermis, sometimes in the tympanum proper, expecting to break up incrustations and separate by evacuation. At the first introduction several pieces of catheter were caught and brought away. Others were washed out, and on using the lithotrite again it be came locked, and would not easily open. By means of incising the meatus, a link which formed a barb with the jaws of the instrument was withdrawn. There proved to be little or no incrustation. DR. R. H. FITZ read a paper on The report of the discussion on this paper is delayed by request of Dr. Fitz. DR. J. ORNE GREEN read a paper on SEROUS EFFUSIONS IN THE TYMPANUM.1 Dr. Green said in answer to Dr. C. J. Blake that he thought paratencesis was indicated in a case of effusion without congestion, provided it were not absorbed by inflation. DR. C. J. BLAKE said that among the causes for hydrops tympani were closure of the Eustachian tube, which commonly includes some congestion; the presence of nasal polypi, when the condition can be removed by the removal of the polypus; and reflexes affecting the vaso-motor nerves of the part. He mentioned a case of exposure to cold during a drive, which was followed in two hours by great pain, with swelling and bulging of the upper part of the tympanum, which was transparent with effusion, although there was no liquid in the middle ear. The condition, if not relieved, would grow worse. Inflation was impossible, and paracentesis caused the collapse of the bulged membrane with a sharp hiss of escaping air. An hour later there was a free serous discharge. He asked the reader if he is ever obliged in these cases to use the Eustachian bougie. DR. GREEN said that he thinks either Politzer's inflation or the catheter can commonly be used in this condition. He would not, however, hesitate to use the bougie if they failed, and he does use it in other forms. 1 See page 553 of this number of the JOURNAL. DR. S. W. LANG MAID expressed his opinion that most people are unable to have the nostrils long occluded without risk of effusion in the ear, and that the risk is increased if there is at the same time a pharyngeal stenosis, from whatever cause. DR. GREEN said that he had not intended to go into anything but the common forms, and he wished to dwell particularly on the diagnosis and treatment. DR. G. K. SABINE asked if there is any value in the common practice of inflating the ear by blowing against the fingers. DR. GREEN thought it would only be possible in simple cases. It is partial, and it may do harm by causing congestion of the whole head, while from the frequency with which the patient is tempted to use it there is danger of stretching the drum. PERCEPTION OF MUSICAL NOTES IN ANIMALS. DR. C. J. BLAKE showed a whistle invented by Francis Dalton in which the pitch is regulated by a screw. By the use of this it is found that small dogs appreciate a higher pitch than large ones. Experiments are now in process on cats. ESSEX NORTH DISTRICT MEDICAL SOCIETY. H. F. ADAMS, M. D., CORRESPONDING SECRETARY, REPORTER. THE regular annual meeting of the Essex North District Medical Society was held at the Eagle House, Haverhill, March 7, 1884, DR. J. A. DOUGLASS, of Amesbury, President, in the chair. The annual address was by DR. E. P. HURD, of Newburyport, Vice-President of the Society; subject CEREBRAL LOCALIZATIONS. The following is a synopsis: The essayist divided his topic into four heads: First, the general physiology of the cerebrum; second, regional physiology; third, psychical evolution and cortical centres; fourth, the explanation. Thousands of observations have confirmed Broca's thesis, and lesions of Broca's convolution extending into the pre-frontal lobes are found to be attended not only with aphasia but with amnesia, loss of the memory of ideas, as well as of words and verbal expression. Other considerations, such as the effect of destruction of these inexcitable (pre-frontal) lobes, go to show that their main function is psychical. Hughlings Jackson thinks that they are par excellence the motor substrata, but if any motor influence emanates from them (and anatomically these lobes certainly seem to be connected through the corona radiata with the motor portion of the cerebro-spinal axis), such motor influence must be of an inhibitory character, that is, restraining rather than exciting. We have certainly instances of motor neurility which is inhibitory in the cardiac branches of the par vagum, the depressor nerve of Cyon, etc. As to the functions of the parietal lobes, Ferrier's carefully conducted experiments seem to prove that they are motor rather than psychical; this is especially true of certain areas of gray matter bounding the fissure of Rolando, electrical stimulation of which produces definite motor results, destruction of these areas being followed by local paralyses, as of limbs. The phenomenon of descending degeneration of the medullary strands between Ferrier's cortical centres and the basal ganglia, in the case of lesions of the so-called motor regions, and the coincidence of this degeneration with similar degradation of the motor columus of the spinal cord, as noted by Charcot and Flechsig, seems to point to direct anatomical connection between the anterior and crossed pyramidal columns of the spinal cord and those cortical regions. Franck and Pitres have obtained similar results by section of the fibres proceeding from the gray matter bounding the fissure of Rolando, secondary degenerations occurring precisely similar to those which are seen in motor nerves after their separation from their trophic centres in the spinal cord, and they reason from this that "the medullary fibres between the cortical centres and the lower motor nuclei bear the same relation to the nerve cells of the cortex as the spinal motor nerves to the multipolar cells of the anterior cornua.” Experimenters working in the same direction with Ferrier (Carville and Duret, Luciani and Tambourini, Under the first head, he said, there was general agreement that the hemispheres were the seat of the intellectual operations and of volition, as proved by mutilations in animals (removal of parts or the whole of the cerebrum) and the effects of disease in man (atro-eral intellectual obtusion. The autopsy disclosed (on the left side) phy, inflammation, oedema, etc.). Grave lesions of the encephalon, whether morbid or experimental, are always attended with enfeeblement or disappearance of the psychical faculties, and it is a fact, too, that motility also suffers in a marked degree. When we come to the matter of regional physiology, we find ourselves in the midst of problems that still await complete solution. The first and capital fact in cerebral localizations was the discovery by Broca in 1861 of the speech centre in the posterior part of the third frontal convolution of the left hemisphere.1 1 The whole subject of aphasia is a complex one, nor have we yet the data for its complete exposition from the stand-point of definite anatomical bases. Broca's convolution is regarded as the seat of language expression, that is, the centre from which volitional incitations to movements of articulation pass downwards. At the same time there are several well-attested cases on record which go to show that lesions in the neighborhood of (that is, posteriorly and below) Broca's centre are attended with aphasia, often with verbal surdity and blindness. I call particular attention to the Contribution to the Study of Aphasia by Dr. Balzer in the Gazette Medicale de Paris, March 1 and 15, 1884. In one of Dr. Balzer's cases there was marked motor aphasia and agraphia with verbal blindness and deafness and gen tion of the inferior parietal lobule, and the pli courbe; that is, the softening of the first temporo-sphenoidal convolution, the lower porcentres of sight and hearing were involved. Here, although Broca's speech centre was not directly affected, it is easy to understand that an extensive lesion in the vicinity might have had a considerable inhibiting influence on that centre, especially when it is taken into consideration that an important branch of the Sylvian artery was left side were destroyed. The language function is so associated found calcified. Moreover, the auditory and visual centres on the with ideation generally, and normal ideation is so dependent on integrity of the perceptive centres, that serious lesion of the latter tial reproduction. In other words, verbal expression must be lackmust impair (if it does not render utterly impossible) all reminiscening when the memory of words is gone. left temporo-sphenoidal lobe was "a mass of pus." There was con Balzer's second case was one of pathological "muteness." The siderable congestion of the inferior portions of the left frontal lobe, and slight adhesions of the membranes. The observation is imperfectly reported, and on the whole is hardly to be regarded as evidence against Broca's doctrine His third observation is carefully reported. It is a case of tuberculous meningitis on the left side, and the general symptoms, coupled with the post-mortem revelations, remarkably sustain the doctrines of localization as propounded by Ferrier. There was right hemiplegia and lesion on both sides of the fissure of Rolando, motor aphasia, verbal blindness and deafness, agraphia with meningoencephalitis of Broca's convolution, the temporo-sphenoidal lobe, and the angular gyrus. Tuberculous meningitis seldom lends itself to the elucidation of cerebral localizations. In this instance the data were sufficient to sanction quite positive conclusions. notably Yeo) have added confirmation to Ferrier's views, and hundreds of clinical and post-mortem observations have demonstrated the concomitance of general or limited paralyses with lesions more or less circumscribed of those portions of the parietal lobes now known as Ferrier's centres. Among the important contributions which have appeared in American medical journals, throwing light on certain aspects of the subject, were signaled the papers by Seguin and Dalton in the Medical Record (1881). The "new phrenology" has been proved a valuable aid to diagnosis by the former, who has found Ferrier's statement of localizations to be, "not theoretical guides, but valuable life laws." The experiments of Dalton go to corroborate the position of Ferrier, that the angular gyrus is the seat of visual perception, blindness following its excision in dogs. The essayist, in taking up the subject of cortical centres with reference to a statement of Exner's modifica tion of Ferrier's localizations, alluded to the views of Brown-Sequard and Goltz that the sensory and motor substrata of function are scattered over wide areas. This is possible by virtue of the well-known multiplicity of fibre connections, but improbable, and it presupposes the occupancy to a greater or less extent of a whole cerebral hemisphere by any voluntary operation. There are strong considerations which favor the theory of localizations in limited areas of the cortex. In this seeming chaos of cells and fibres there must be orderly arrangement. If the cerebral hemispheres be a representation of inner relations answering to the most stable relations of the external cosmos, the order in the inner world must correspond with the order without. The law of physiological distribution of labor must apply to the cerebrum as well as to other parts of the economy. When you move your hand citation comes from a definite region of the cortex. It will always under similar circumstances come from the same cortical region. The fibres of the corona radiata which carry visual impressions to the cortex must pursue a definite route. Other sense impressions must follow, as it were, a beaten track to some region of the gray matter near the surface, when they are for a time concentrated, to be afterward, it may be, widely dif fused, and blended with fibres of different sensory nature, and motor fibres. That the visual, auditory, and tactile centres occupy a wide area of the cortex seems probable when we consider the part which they have in building up the fabric of our mental experiences. Allusion was made to numerous cases on record of abscesses of the hemispheres which have been diagnosticated by the local paralytic symptoms. The skull has been trephined, the abscess evacuated, and recov-in obedience to a voluntary impulse, such motor exery has followed the operation. It is worthy of note, too, that Dr. Hughlings Jackson, reasoning from clinical and pathological observations of unilateral and localized epileptiform convulsions, formulated in advance of any experiments of Fritsch and Hitzig views of the aetiology of these convulsions, which are found to be in accordance with Ferrier's observations and those of his German predecessors. These obscure forms of epilepsy, referred by Jackson to irritative or discharging lesions of Ferrier's centres, are now known as "Jacksonian epilepsy." With regard to the various sensory centres (auditory, visual, gustatory, tactile, etc.) there is still great uncertainty; experimenters are not agreed as to the precise location of these centres in the cortex, nor as to the function of the occipital lobes. Under his third head (psychical evolution, etc.) the essayist discussed the ancient phrenological hypothesis, which he considered unfounded and absurd. He advocated the evolutionary doctrine, which teaches in opposition to the old view that mind is constituted by an assemblage of distinct faculties, having their seats in separate regions of the cerebral cortex-that "intelligence has neither distinct grades nor is constituted of faculties that are truly independent; its highest phenomena being the effects of a complication that has arisen by insensible steps out of the simplest elements." The only division of mind that has stood the test of the ages is the threefold division of intellect, feeling, and volition, and yet these three aspects of mind are, as Bain teaches, so dependent among themselves, although characteristic in their manifestations, that no one could exist alone, and feeling is the basic substance of mind. Intellect, moreover, is separable into only three factors: discrimination, or consciousness of difference; similarity, or consciousness of agreement; and retentiveness, or the power of memory or acquisition. The above being premised, it seems a necessary conclusion that identical parts of the brain are concerned in all the phenomena of mind. The division of the cerebral hemispheres into lobes is artificial. There is everywhere intermingling of nerve fibres and nerve cells, and the closest blending of intercellular processes. The arrangements for diffusion of "nerve currents are of the most perfect kind. Multiple as are the neural manifestations, there is practically, through all, the solidarity of a single unit. These opinions are in harmony with those expressed by H. Charlton Bastian in the "Brain an Organ of Mind," and other authorities. Bastian, who charily and reservedly admits the doctrine of localizations as applied to topographically distinct foci of sensation, while admitting the essential facts of motor localizations, was the first formally to propound the theory of “Percep tive Centres in the Cortex " in the Journal of Mental Science, 1869; also to state the view, supported of late by Exner, "that there may be much and compound overlapping of areas, and though the area pertaining to the impressions of any particular sense in the cere bral hemispheres may be a very extended one (not to speak of the still further complication brought about by the communication established between the nerve cells of the sense area with those of others in the same hemisphere, and the opposite hemisphere), still it may well be that certain portions of the surface of the cerebral hemispheres might correspond more especially to the maximum amount of nerve cells and fibres pertaining to some one or other of the various senses." This theory of the overlapping of sense centres in the cortex and the wide diffusion of their cellular and fibrous connections has received striking confirmation from Exner's studies, to which attention was called in an editorial article in the Medical Record for April 15, 1882. According to Exner the cortical centres are rather areas of functional concentration than sharply demarcated sensory and motor foci, and the diffusion and interblending of fibres which there occur and the overlapping of one district by another afford a plausible explanation of the different results which have been noted in lesions of these districts, also of the recovery from functional paralysis which in animals so often The cortical field of vision, according to Exner, corresponds more exactly with the region assigned to this sense by Muhr and Monk than to that assigned to it by Ferrier, namely, the angular gyrus. This perceptive centre has a relatively wide area in the upper and middle occipital lobes, extending thence into the cuneus. Here again Bastian's view is justified. According to Exner's observations the tactile fields correspond very closely with the motor fields for the same body regions, and this is in striking confirmation of the studies of Betz and Luys on the functional significance of the cells in the stratified zones. Luys believes that the submeningeal region, principally occupied with small cells, is especially connected with the phenomena of sensation, while the deeper regions, occupied by large cells (triangular cells of Luys, giant cells of Meynert), may be considered as the most important regions that give rise to motor phenomena. In studying this question Luys bases his conclusions principally on data acquired from a study of the spinal cord, which show that the regions of small cells have sensory functions (posterior cornua), while the regions of large cells (anterior cornua) are motor. Betz's special contribution to this micrographical study is that the large, so-called motor cells predominate in the neighborhood of the fissure of Rolando (Ferrier's excitable motor region). The essayist in concluding remarked as follows: "On the whole the doctrine of localizations as propounded by Ferrier, with some probable modifications as above indicated, seems likely to be triumphant along the whole line. "The question now presents itself, What is the explanation of this doctrine? What theory will best string together all these facts? "The cerebral hemispheres, gentlemen, are, if we read comparative anatomy aright, a budding forth, an outcropping of the opto-striate bodies, the great sensorimotor ganglia; they are certain stories, as it were, added on to basal ganglia, and were called by Solly the hemispherical ganglia. The enormous augmentation of cells and fibres which compose these cortical centres bespeaks in the organism a higher and more complex system of adjustments of inner to outer actions, an extension of the correspondence in space and time, involving an increased amount of life and a longer continuance of life. Accumulating experiences in the race caused augmented development of the anatomical substratum representing those experiences, with its elaborate system of connections whereby those experiences are compared, and become combined and coördinated. As "I wish to be understood as hypothecating an immanent divine force raising matter through evolution to the sublimest organic plane, and developing out of the lowest nervous activities the highest powers of mind. "I desire now to insist on the following points in elucidation of this difficult subject: If the cerebral hemispheres be an extension of the basal ganglia then the functions of these hemispheres caunot be essentially different from the functions of the basal ganglia. suming this we should expect, a priori, to find the same orderly arrangements for motor coördination in the cortex as we find in the lower ganglia, and as there is progressively an increase in the complexity of coordinations as we ascend the cerebro-spinal axis, so we are warranted in regarding the cerebral convolutions as the highest centres of muscular combinations, representing on a larger scale the combinations of the lower centres. Such being the case, as there are tracts in the inferior portions of the cerebro-spinal axis whose lesion causes local paralyses, so we should expect to find definite areas in the cortex whose lesion also would cause paralysis of a more or less local and limited nature. I have already shown that the facts are in harmony with this view. The gray matter in the neighborhood of the fissure of Rolando with its fibrillary prolongations in the corona radiata seems to contain the centres through which the will (I use this old metaphysical term to avoid circumlocution) acts downward on the corpus striatum, calling into play new cell combinations and the appropriate motor mechanism. With respect to the sensory and perceptive functions of the basal ganglia, called the sensorium by Dr. Carpenter, I would regard the cortical centres as simply the complement of those basal centres. Much confusion has been introduced into cerebral physiology by endeavoring to make an essential difference be tween the intelligential functions of the cerebral hemispheres and those of the sensorium, so called. The difference is only one of degree, not of kind. Luys is undoubtedly right in making of the optic thalamus a perceptive centre, in opposition to Dr. Carpenter, who considers it the centre of brute sensation. Every sensorial impression is to some extent perceived in the thalamus, although the elements constituting the complete perception of an object are largely supplied by the cortex. I would, then, style, after Luys, the sensory portion of the cortex the centres of augmented and completed perception. Such being the case I see no difficulty in understanding how the seats of common 1 This view (of overlapping and diffusion) does not seem to me to be essentially different from that advocated by Dr. Hughlings Jack-sensation and of special sense in the thalamus should son in his recent Croonian Lectures. "It may be said that one con volution will represent only the movements of the arm, another only those of speech, another only those of the leg, and so on. The facts show that this is not the plan of structure of the nervous system. Thus, to take an illustration, the external parts, x, y, and z, are each represented by units of the corpus striatum. But the plan of representation is not that some units contain x largely only, as x3, others y largely only, as y3, but that each unit contains x, y, and z; some, let us say, as x3, y2, z; others as x2, y, z, etc. When we come to the still higher evolution of the cerebrum we can easily understand that if the same plan be carried out a square inch of convolution may be wanting without palsy of the face, arm, and leg, as x, y, and z are represented in other convolutions, and we can also easily understand that discharge of a square inch of convolution must put in excessive movement the whole region, for it contains processes representing x, y, and z with gray matter in exact proportion to the degree of complexity." This doctrine of compensation, Dr. Jackson thinks, applies to representation of movements in the mid cerebral region of dogs. Destruction of a part of the dog's mid cortex entails no permanent paralysis, but discharge of any part of it produces convulsion. - London Lancet, April 26, 1884, page 743. have their representatives in the hemispheres. It may well be, moreover, that these cortical centres by education and development do finally in the highest creatures acquire such predominance that without their coöperation every sense impression shall be confused, unreal, or even nil. Hence the blindness that follows destructive lesion of the angular gyrus, and which in the lower animals is said gradually to be recovered from, probably by, the lower sight centre, which Luys locates in the thalamus, gradually taking on increased function. These are abstruse subjects, a provisional solution of which must for the present be sought in deductions from the general doctrine of evolution, which is shedding so much light on all difficult physiological prob lems." |