A junior course of practical zoology / by A. Milnes Marshall, assisted by C. Herbert Hurst.

  • Arthur Milnes Marshall
Date:
1887
Catalogue details

Licence: Public Domain Mark

Credit: A junior course of practical zoology / by A. Milnes Marshall, assisted by C. Herbert Hurst. Source: Wellcome Collection.

    439/472
    VIII. EXAMINATION OF THE BE AIN. A. Removal of the Brain. Cut through the skin of the top of the head along the middle line, and turn the flaps aside. Expose and scrape clean the hones of the roof of the skull. Slice off with a scalpel the skull-roof, taking care not to injure the brain, which lies very close to the bone. Cut away, bit by bit, the roof and sides of the skull, with the scalpel and stout scissors, so as to expose the brain thoroughly. Eemove the neural arches of the first two vertebrce, and divide the spinal cord transversely. Turn out the brain careffdly, cutting across the several nerve-roots one by one. Place the brain in a bottle of strong spirit, with a pad of loose cotton-iuool at the bottom, and leave it for two or three days until it is thoroughly hardened. Examine it in water or in weak spirit. B. External Characters of the Brain. 1. The dorsal surface. a. The cerebral hemispheres are a pair of large pyri- form bodies, closely applied to each other in the median plane. Their surfaces are nearly smooth, and their anterior ends bluntly pointed. b. The olfactory lobes are a pair of small conical bodies, projecting forwards from the anterior ends of the hemispheres. c. The pineal body is a small oval body, immediately behind the hemispheres, and in the angle between them. d. The optic lobes are a pair of smooth ovoid bodies at the sides of the brain, behind and rather below the hemispheres. e. The cerebellum is a median elongated oval body, marked by a number of transverse fissures. In front it is in contact with the hemispheres; behind, it overlaps the medulla ; and laterally, it lies above the optic lobes.