motor writing apparatus, excepting in the case of some automatic combinations, such as his signature. For similar reasons he can not write from dictation. The hemianopic cases, however, write spontaneously and from dictation with ordinary facility, as in these cases the visual word memories are not necessarily destroyed, but only cut off from the lower half-vision cortex in the occipital apex. They are unable, however, to read what they have written. Spoken language is both understood and expressed with complete readiness. When familiar objects are not recognized, mind-blindness is present and the lesion is probably bilateral. It appears that ordinary visual sensations, as sensation in general, are symmetrically represented. The educated faculty of visual word memories is represented in the left angular gyre alone.

Exner

Graphic-motor Aphasia.-Regarding this variety of aphasia there is much dispute and uncertainty. According to some, Wernicke in particular, the act of writing is but the act of tracing the visual word memories. He points out that this can be done with the left hand, the elbow, the foot, or even with a pencil held between the teeth. maintains that there is a graphic-motor center in the foot of the second frontal convolution adjoining the centers for the hand, but this is not sufficiently verified. The facility with which the right is used as compared with the left hand, or the other portions of the body, indicates that it has attained a proficiency quite its own, which must be resident in its principal cortical representation. Some persons write with small finger movements, others with a wide, full arm-sweep, the pen being simply grasped with the hand, which is largely guided from the shoulder. An ambidexter uses either hand. Their cortical writing apparatus must vary correspondingly. In persons deprived of both hands, who write with the foot, quite another cortical area must be educated for the purpose. It seems probable that in every case this education would fall upon the corresponding sensorimotor cortex, which develops specially intimate relations with the area of visual speech. Even this relation is not absolutely required, as the blind accurately reproduce the letter forms they have learned by the sense of touch.

It seems unnecessary to presume the existence of a higher graphicmotor center. A lesion which upsets the motor memories of writing would, therefore, probably paralyze the muscle groups used in the act, and it would be impossible to decide whether the difficulty arose from the obliteration of specialized motor memories or those proper to the member. In such cases the left hand writes as readily as ever if the visual word memories are not impaired.

It will be recalled that agraphia is common in motor and usual in auditory aphasia. In auditory aphasia we more commonly have paragraphia, unless the lesion also involves the visual speech-cortex. The usual proportionate relation of agraphia to motor aphasia early suggested to Broca and Trousseau that the motor speech-center must control this form of emissive expression as well as that by the oral apparatus. There is a general inclination to return to this view.

Conduction Aphasias.-The aphasias thus far considered are due to lesions of single memory depots. There are others due to lesions of the

conducting tracts that bring these depots into mutual and coördinate relations. The most important is the one produced by breaking the path between the auditory and motor word-centers. This is usually due to a lesion of or in the neighborhood of the island of Reil. It was first described by Wernicke and is sometimes called Wernicke's conduction aphasia. These patients present no particular auditory or articulative difficulty, but, owing to the loss of correlation between auditory and motor memories, they lose selective ability when they try to express themselves, and a most marked paraphasia and paragraphia result. They are obedient to direction, but can not repeat dictation orally or in writing, though they copy with perfect precision. Neither can they read or pronounce aloud, though they seem to read understandingly. There is very little attempt to correct errors of spoken or written speech. The writer has seen such a case, due to traumatic hemorrhage, which was relieved by operation, the clot being found under the operculum on the surface of the insular convolutions, where it had been located from the symptoms. The recovered patient now states that there was considerable mental confusion during the aphasia, to which the verbal disturbance no doubt would conduce.

Wernicke, Lichtheim, Wyllie, and others describe four other varieties of conduction aphasia depending upon the location of the lesion in relation to the conducting tracts to and from the auditory and motor word memories. Some quoted cases also are given in their support. Anatomical findings as yet are scarcely adequate to firmly establish these varieties, which, however, serve to complete the pathological study of the subject. By their aid some rare instances can be deciphered.

Combined Aphasias.-It has been pointed out that all the wordmemory depots are in the arterial territory of the middle cerebral. Consequently from this source, as well as by trauma, meningitis, or cerebritis, they may all be thrown out at once. Simultaneous injury to the auditory and visual word memories is comparatively frequent, and it has been seen that graphic-motor memories usually disappear with vocal motor memories-a combination due not only to association in function, but to proximity of centers, if a special one for writing is admitted. The loss of auditory and motor memories practically entails a loss of all speech attributes, as the visual and graphic-motor centers are so thoroughly dependent upon them. Again, the centers may be unequally affected, so that sensory disturbance preponderates over motor, or the contrary. The type cases indicated in the foregoing pages are indeed rare, but only by their full comprehension can we unravel the combined forms.

The mental disturbance is usually proportionate to the speech defect, and in total aphasia is very marked.

Reeducation of Aphasics.-One of the most important questions in a given case of aphasia regards recovery from the speech defect. Pure motor aphasia is perhaps the most hopeful variety in this respect, as verbal motor memories are the most easily built up. Reading usually follows much more slowly and writing is even more tardy. The forms of aphasia connected with the loss of sensory word memories are the

most persistent. As often mentioned, a majority of persons are auditif, and all are necessarily so in childhood. Here, too, the mental disturbance is usually greatest. The loss of these earliest and usually most deeply graven memories, which become dominant in the speech mechanism, is the most difficult to overcome.

The first step is to determine by which route the intelligence may best be reached. Even when both auditory and visual memories are gone some patients can use the sense of touch to good advantage, and it will often be found an aid to put familiar objects into their hands when encouraging them to name them. If they are capable of giving steady attention, much may be expected. Simple sounds, such as a child first utters, like ba, pa, ma, may be indicated to them and repeated by the voice and in writing, by the position of the lips, mouth, and tongue of the instructor, or by taking the patient's hand and tracing the letters either in air or on a blackboard. If some object can be used,-say, a knife or pen,-it should be kept before the patient and placed in his hand when he attempts to name it. When simple sounds are mastered they can then be grouped into words, and the words associated with objects or actions, and so a vocabulary built up, which must be frequently and repeatedly and patiently rehearsed. By unremitting, intelligent effort, some emissive speech may be taught even the most hopeless cases. It adds greatly to their comfort and makes their care less burdensome.

CHAPTER III.

THE CEREBRAL WHITE MATTER, BASAL GANGLIA, AND CEREBELLUM.

DESCENDING from the cortex in converging lines we have the corona radiata, the fibers of which bring the brain-mantle into relation with the lower brain parts and the spinal cord. Through the corpus callosum the homologous cortical elements on the two sides of the brain are brought into harmonious relation. The descending tracts reaching the basal ganglia are condensed into the internal capsule, in which the cortical motor fields are represented from head to foot, in an order from before backward, as indicated in figure 71.

The internal capsule lies between the lenticular part of the striate body externally and the caudate nucleus and the optic thalamus on its median aspect, but is not dependent upon them. Its anterior portion, or limb, is supposed to contain psychic paths to the frontal lobes. Lesions of this part of the internal capsule produce no distinctive symptoms. The motor routes lower down are continued in the under portion of the crura and so on through the pons into the medulla and cord. The motor paths and their relations are indicated in figure 72, which shows that the

face mechanism is inferiorly situated in the cortex, anteriorly in the capsule, and internally in the crus.

Fig. 71.-Arrangement of motor paths in the internal capsule (after Ferrier).

From these diagrams we can understand why it is that lesions in the