Outlines of comparative physiology touching the structure and development of the races of animals, living and extinct : for the use of schools and colleges . 46 NERVOUS SYSTEM AND GENERAL lumns of the medulla expand in its interior, giving off brancheswhich are covered by grey substance, and forming an arborvitse. The optic lobes are considerably developed, and seenat b, behind the hemispheres. When these bodies are separated,/• we observe the anterior commissure bound- ing the third ventricle ; pineal and pituitarybodies are distinct; the hemispheres aregreatly increased in volume
Outlines of comparative physiology touching the structure and development of the races of animals, living and extinct : for the use of schools and colleges . 46 NERVOUS SYSTEM AND GENERAL lumns of the medulla expand in its interior, giving off brancheswhich are covered by grey substance, and forming an arborvitse. The optic lobes are considerably developed, and seenat b, behind the hemispheres. When these bodies are separated,/• we observe the anterior commissure bound- ing the third ventricle ; pineal and pituitarybodies are distinct; the hemispheres aregreatly increased in volume in this class;they are still smooth, without convolutionsand posterior lobes. The absence of thelatter permits us, when we open the skull,to see the optic lobes lying behind 27.—The brain The olfactory nerves, with their ganglionicof a pigeon. enlargement, are seen in fig. 27, which re-presents the base of the brain of a pigeon, a, is the hemi-spheres; b, the optic lobes; c, the cerebellum; 1 to 6, pairs ofnerves. The olfactory nerves arise at the an-terior and inferior parts of the anterior lobes7j of the hemispheres; the corpus callosum is re-presented by a feeble rudiment in
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectzoology, bookyear1870
