FUNCTIONS OF THE CEREBRUM. 795 



muscles concerned in articulation. Thus regarded, aphasia does not include aphonia from 

 laryngeal disease, or loss of speech such as is observed frequently in hysteria, in the in- 

 sane, who sometimes refuse to speak from pure obstinacy, or in cases of paralysis of the 

 parts immediately concerned in articulation. The whole history of the disease points to 

 a particular part of the brain, which presides over the faculty of speech. 



As a preliminary to the location of the nerve-centre presiding exclusively over speech, 

 it is necessary to establish the existence of the power of articulate language as a distinct 

 faculty ; and this is done by cases of disease in which this faculty seems to be lost, the 

 general mental condition being unaffected. Passing over the passages in the writings of 

 the ancients, in which it is stated that the power of speech is sometimes lost, and even 

 some writers in the beginning of the present century, who connected this difficulty with 

 lesions of the anterior lobes of the brain, we come to the observations of Dr. Marc Dax, 

 who, in 1836, read a paper before the medical congress at Montpellier, in which he indicat- 

 ed impairment or loss of speech in one hundred and forty cases of right hemiplegia. Dax 

 concluded, from these observations, that the faculty of articulate language occupies the 

 left anterior lobe of the cerebrum. This memoir, however, attracted but little attention, 

 until 1861, when the discussion was renewed by Broca; and, since then, numerous cases 

 of aphasia with lesion of the left anterior lobe have been reported by various writers. In 

 1863, M. G. Dax, a son of Marc Dax, limited the lesion to the anterior and middle portion 

 of the left anterior lobe. It was farther stated, by Broca and Hughlings Jackson, to be 

 that portion of the brain nourished by the left middle cerebral artery. According to 

 recent observers, the most frequent lesion in aphasia is in the parts supplied by the left 

 middle cerebral artery, particularly the lobe of the insula, or the island of Reil ; and it is 

 a curious fact that this part is found only in man and monkeys, being in the latter 

 very slightly developed. While we must agree with most authors in the statement that 

 the organ of language cannot be absolutely restricted to these parts, it is none the less 

 certain that they are most frequently the seat of lesion in aphasia. 



While it is demonstrated that the cerebral lesion in aphasia involves the left anterior 

 lobe in the great majority of cases, there are several instances in which the right lobe 

 alone is affected ; and this has led physiologists and pathologists to deny the absolute 

 location of the organ of language upon the left side. Even if we reject a certain number of 

 cases of aphasia with the brain-lesion limited to the right side, in which we may suppose 

 that the post-mortem examinations were incomplete, or the impairment of speech was 

 due, perhaps, to simple paralysis of muscles, we must admit that, in a few instances, 

 aphasia has followed injury or disease of the brain upon the right side. Aside from 

 the anatomical arrangement of the arteries, which seem to furnish a greater amount of 

 blood to the left hemisphere, it is evident that, as far as voluntary movements are con- 

 cerned, the right ha^nd, foot, eye, etc., are used in preference to the left ; and that the 

 motor functions of the left hemisphere are superior in activity to those of the right. It 

 would be interesting, then, to note the physical peculiarities of persons affected with left 

 hemiplegia and aphasia. Dr. Bateman quotes two cases of aphasia dependent upon lesion 

 of the right side of the brain and consequent left hemiplegia, in which the persons were 

 left-handed ; and these, few as they are, are interesting, as showing that a person may use 

 the right side of the brain in speech, as in the other motor functions. In this connection, 

 it may not be uninteresting to note that, although most anatomists have failed to find any 

 marked difference in the weight of the two cerebral hemispheres, Dr. Boyd has shown 

 by an " examination of nearly two hundred cases at St. Marylebone, in which the hemi- 

 spheres were weighed separately, that almost invariably the weight of the left exceeded 

 that of the right by at least the eighth of an ounce." To conclude our citations of patho- 

 logical facts bearing upon the location in the brain of the organ of speech, we may refer 

 to an account, by Dr. Broadbent, of the brain of a deaf and dumb woman. In this case 

 the brain was found to be of about the usual weight, but the left third frontal convolu- 

 tion was of " comparatively small size and simple character." 

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