Diseases of the nervous system / edited by Archibald Church.

Date:
1908
Catalogue details

Licence: In copyright

Credit: Diseases of the nervous system / edited by Archibald Church. Source: Wellcome Collection.

    60/1256 (page 32)
    occipital lobes, while the temporal bone covers the temporal lobe, and the high- est point of the squamous suture reaches the Sylvian fissure. Under the plate of the occipital bone lie the occipital lobes and the cerebellum. A number of methods have been proposed by which to determine the fissures which should be traced in operations, especially the Sylvian fissure, the central furrow, etc. Waldeyer, in a very instructive article, “ The Topography of the Brain,” 1 recently described the most important relations of these, combining the chief features in the systems of Thane, Poirier and others. Here I shall cite only the main points enumerated by Waldeyer. (a) During life, the lower end of the central furrow may be traced exter- nally on the skull by drawing a German horizontal (a line from the deepest point of the infraorbital border through the highest point of the upper border of the porus acusticus externus) at a right angle from the tragus close behind the jaw and upon this a line extending 5 to 6 cm. upward; (b) The upper end of the central sulcus is found by tracing a perpendicular line upon the posterior circumference of the base at the point where the mastoid process intersects the edge of the hemisphere; (c) The Sylvian point, the point of division of the Sylvian fossa, is situ- ated at a point 4 to 4.5 cm. perpendicularly above the middle of the zygo- matic arch. (d) The upper end of the Sylvian fissure corresponds to the middle of the lower border of the parietal tuberosity; (e) The parieto-occipital fissure is found on the lambda where the lamb- doid and sagittal sutures unite. Besides the direct topographic relations of the brain and skull an inter- esting question is, in how far the development of definite portions of the brain is manifested by the shape of the bony skull, and in how far an examination of the latter permits us to draw conclusions as to the development of the brain of any particular person. It is known that, at the beginning of the nineteenth century, the discussion of this point led the great investigator, Gall, to entirely erroneous conclusions; he divided the skull into various regions, and the greater or less development of these areas was supposed to indicate greater or less mental development along certain lines. Even during the lifetime of Gall there was great opposi- tion to this teaching, which actually impaired the value of Gall’s otherwise great services, for subsequent exact investigation of the brain and its faculties proved these theories to be absolutely incorrect. Lately Möbius has reverted to Gall’s teaching inasmuch as he regards an unusually marked development of the upper external angle of the orbit (which, according to Gall, is the seat for the sense of figures) as a sign of especial mathematical power, as a “ mathe- matic organ,” due to an abnormal and increased development of the anterior end of the third, frontal convolution. This view which Möbius proposed has not as yet been generally accepted nor has it been confirmed by others. On the other hand Schwalbe, in the Festschrift, issued upon the occasion of Kuss- maul’s 80th birthday, described the “ relations of the internal and external conformation of the skull ” and has shown that a part of the rilievo of the brain is recognizable upon the external surface of the skull, best in those i Deutsche med. Wochenschr., 1901, Nr. 26 et seq.