. Anatomy, descriptive and applied. Anatomy. 912 THE NEBVE SYSTESr The Cerebral Hemispheres. External Morphology.—Of all the component parts of the brain, the cerebral hemispheres form the largest part, and their preponderance and remarkable specialization underlie the extraordinary manifestations of the intellect so highly amplified in Fig. 673.—^Tesal aspect of a brain sectioned in the median sagittal plane. The term cerebrum, often employed loosely as embracing several brain parts, is here intended to include the brain mantle and the olfactory lobe—equivalent to the telencephalon of H
. Anatomy, descriptive and applied. Anatomy. 912 THE NEBVE SYSTESr The Cerebral Hemispheres. External Morphology.—Of all the component parts of the brain, the cerebral hemispheres form the largest part, and their preponderance and remarkable specialization underlie the extraordinary manifestations of the intellect so highly amplified in Fig. 673.—^Tesal aspect of a brain sectioned in the median sagittal plane. The term cerebrum, often employed loosely as embracing several brain parts, is here intended to include the brain mantle and the olfactory lobe—equivalent to the telencephalon of His, with the exception of the pars optica hypothalami. As already indicated in the section on brain development, there has occurred, in the evolutionary history of man's vertebrate ancestry, a progressive increase of the secondary fore-brain, with concomitant reduction of the rkinencephalon, or smell brain—the most archaic portion because of the important relations of the smell sense to the life history of the earliest \'ertebrates.^ In a mesal view of a hemisected brain (Fig. 673) may be seen the various parts of the brain stem and the cerebellum overlapped by the preponderatingly greater cerebrum. Among the many notable features exposed to view in this brain section are certain fibre masses, commissures, extending across the meson, and therefore divided by the knife in this preparation. Of the commissures pertaining to the cerebrum one is conspicuous for its size and firm consistency. This great fore-brain commissure is the corpus callosum already mentioned as being demon- strable in the depths of the intercerebral cleft on divaricating the lips of this fissure. The corpus callosum constitutes a massive system of association fibres for the bilateral coordination of corresponding cortical parts. It is thickened caudally, forming the splenium of the corpus callosum; frontad it bends on itself • For a more thorough discussion on the natural subdi-vision of the fore-bra
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectanatomy, bookyear1913
