for audited language in the left first temporal gyrus? In this department of pathology medical science has been strictly inductive and sufficient unto itself, though receiving confirmatory evidence from the physiologist. The first (speech) and the last (visual) centres have been discovered by clinical and pathological studies.

Horsley's figure is reproduced partly to illustrate his topographical method, and partly because of its value for surgical purposes. The figures illustrating Broca's method of cranio-cerebral topo

graphy will be found on p. 42 of vol. ii. of Gross' "System of Surgery," Phila., 1882, and Pepper's "System of Medicine," vol. V., p. 94.

At the meeting of the Sixth Congress for Internal Medicine held at Wiesbaden, two very important referees' papers on cerebral

localization were presented. The first, by Nothnagel,2 relates to the localization of lesions in the visual centre and in the various motor centres. The author considers it as demonstrated that in the human brain there is localization of function in various parts of the cortex. As regards hemianopsia, he admits that its lesion involves one cuneus, but would add to this as part of the centre gyrus O', which we are not prepared to contest. He explains the hemianopsia caused by lesion of the angular gyrus or the inferior parietal lobule by injury to the subjacent fasciculus opticus, without stating that this explanation was first advanced by the writer of this review in 1886.3 The remaining occipital convolutions constitute an additional centre for visual residua, and lesion of them causes psychic or soul blindness, as contradistinguished from coarse objective vision. The precise localization or limitation of this area for psychic vision is as yet undetermined. He suggests that as the occipital gyri exhibit frequent variations in form and arrangement, we may look for somewhat variable localization of functions. The paragraphs on motor localization contain several interesting propositions. In the first place Noth

nagel declares that he has never observed loss of muscular sense in cases of lesion limited to the motor area, though a degree of tactile anæsthesia is usually present. In such cases the patient, though the arm or leg is completely paralyzed, yet remembers and is conscious of the nature and direction of movements he would wish to make. In the second place, Nothnagel finds, with a few authors preceding him (myself among them1), that lesions of the inferior parietal lobule produce loss of muscular sense with little or no paralysis or analgesia. From these facts he draws the important conclusions, which seem to us warranted by the facts now in our possession, that the parietal lobe in its inferior part contains a centre for the registration of motor residua, and that the centres in the motor zone are really motor

centres.

The second paper, by Naunyn, is an excellent example of the inductive geometric method, somewhat after Exner, relative to cases of aphasia from cortical lesions. He analyzes 71 cases of aphasia, classified as motor, sensory (acoustic), and undefined aphasia. He then locates the numbers representing the lesions of these cases upon a diagram of the cerebral hemisphere subdivided

Maximum foci of disease in 71 cases of Aphasia (Naunyn)

Cortical area for motor aphasia (Broca.)

Cortical area for aphasia with word-deafness (Wernicke)

Cortical area for aphasia with alexia or word-blindness

From Transactions Sixth Congress of Internal Medicine J F.Bergman Pub Wiesbaden

into small squares: the accumulation of figures in certain areas of the diagram indicates the centres for various special functions. As a result, he finds that the lesion of motor aphasia (true aphasia) is in the basal part (foot) of the left third frontal gyrus, or Broca's centre; that the lesion of sensory aphasia with word-deafness is in the upper extremity of the first temporal gyrus (Wernicke's centre); and that in all probability the lesion in cases of wordblindness (alexia) is in the parieto-occipital area, involving the posterior part of the inferior parietal lobule and the first occipital gyrus. The plates illustrating the general results are herewith reproduced. Naunyn supports the now classical doctrine that all aphasia-producing lesions are in the left hemisphere, except in the case of truly left-handed persons, when they are in the right hemisphere. In this, as in almost all recent contributions, Broca's proposition, formulated in 1861, long before any physiological demonstration of "cortical centres," is sustained,—a striking evidence of the superiority of the clinico-pathological method of study. It should be added that Naunyn guards his conclusions with the statement that he does not think that the above-mentioned centres or areas have definite limits, and that there may be variations in different human brains as regards fasciculation of white substance and superficial arrangement of corresponding cortical areas; all of which is, we may say, a generally admitted qualification to the doctrine of cortical localizations.

In striking contrast to these two valuable papers, produced by strict adhesion to the inductive method, is the report of the discussion on the localization of the muscular sense in the Neurological Society of London, December 16, 1886. Although frequent reference is made to physiological experiments (mostly English), the whole form of the discussion is unscientific and abstract; entire series of known facts are left out of consideration, which, while they do not fully settle the question under debate, yet to a certain extent simplify it and point out the way for further postmortem study. We refer more especially to the fact that in cases of destructive lesions of the motor gyri or of parts of them, the muscular sense is not lost; to the fact that when the lesion affecting the motor zone extends caudad, so as to involve the parietal lobules (the inferior particularly), the muscular sense is lost; to the few but most valuable facts that when a lesion destroys the inferior