Cortical lamination and localisation in the brain of the marmoset / by F.W. Mott, E. Schuster and W.D. Halliburton.

  • Frederick Walker Mott
Date:
[1909]
Catalogue details

Licence: In copyright

Credit: Cortical lamination and localisation in the brain of the marmoset / by F.W. Mott, E. Schuster and W.D. Halliburton. Source: Wellcome Collection.

Provider: This material has been provided by King’s College London. The original may be consulted at King’s College London.

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    in the preservation of the animal, consequently the olfactory nerves and the archicortex are relatively less developed, but the occipital cortex is more developed, and forms a definite occipital lobe covering the cerebellum. The relative extent of the motor area and tactile motor or kinaesthetic area of the neo-cortex of the Marmoset, compared respectively with that of the Lemur and with that of the Macacus rhesus, shows that it corresponds more with the former than with the latter. This fact may be correlated with the following statement by Bates concerning the habits of the Marmoset: “ they are arboreal animals, but their manner of climbing resembles that of squirrels rather than monkeys ; this is due to the fact that they have no means of gripping a bough since the pollex is not opposable, neither is the tail prehensile. They therefore confine themselves to the larger branches, where their long claws are of assistance in enabling them to cling securely to the bark.” The Marmosets, owing to their claws and non- opposable pollex, are unable to use their limbs for prehension with anything like the delicacy and refinement of the higher Apes. Although the Marmoset possesses stereoscopic vision, it is unable to translate all visual into tactile-motor impressions to the same degree of perfection as the Macacus, consequently the stereognostic sense must be comparatively rudimentary. This fact may account for the existence of a convoluted parietal lobe which indicates a considerable extension of surface lying between the occipital lobe and the post-central convolutions in the Macacus, which is not found either in the Lemur or in the Marmoset. General Description of the Brain. The Marmoset has a small brain, and the surface is broken by unusually few fissures. On the external surface the Sylvian fissure (F. S., fig. 2) is the most conspicuous, and there is also an indication of a lateral sulcus (f. pa.) on the temporal lobe. On the under side of the temporal lobe the rhinal fissure (f. rh.) is found, and it may be noticed that it does not come so far around as in the Lemur, where it is seen on the external surface. Thus in the Lemur there is a larger space between the hippocampal and the rhinal fissures, and, therefore, a more extensive olfactory area than in this animal. On the orbital surface a small orbital sulcus appears. An unbranched calcarine fissure (f. cal.) is seen on the mesial surface extending from the hippocampal nearly to the extremity of the pole. A small hippo- campal tubercle lies in front of this hippocampal fissure, and a short inter- calary sulcus appears above the corpus callosum, while in the frontal region there is an indication of a small fissure. These sulci, however, are only
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