The brain : its development, architecture, functions and education a lecture delivered in the Assembly Rooms, Grahamstown, on 18th May, 1892 / by T. Duncan Greenlees.

  • Greenlees, T. Duncan.
Date:
1892
Catalogue details

Licence: Public Domain Mark

Credit: The brain : its development, architecture, functions and education a lecture delivered in the Assembly Rooms, Grahamstown, on 18th May, 1892 / by T. Duncan Greenlees. Source: Wellcome Collection.

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    reach its height in the frog which animal it is convenient to study owing chiefly to its commonness. If the brain be removed from a frog it will still live and respond to various stimuli. If we prick the brainless frog’s leg it will puil it in; if it is placed in hot water it will endeavour to escape, but it does not leap away after we have given over annoying it; it lies down perfectly quietly unless again disturbed by any irrita¬ ting stimulus which causes pain. We note, therefore, that in the frog the sensation of pain is referred to the spinal cord, that it is capable of exercising power of the muscles for some definite object viz., to remove any¬ thing irritating it. Were it possible in a man to remove his brain without causing death, he would feel no pain and his power over his muscles would be totally abolished. We conclude, accordingly from our experi¬ ments, that the spinal cord in the frog is not only spinal cord but likewise brain, and that it is the more important organ of the two; but as we progress on our evolutionary way, the brain increases in importance while the spinal cord remains stationary, or even retrogrades, so far as the functions of the two organs are concerned. We say, therefore, that the spinal cord in the mam¬ malian order of animals, including of course man himself, occupies only a secondary pos¬ ition in the nervous system. Having now reached the Mammalian or¬ der, we may take the dog’s brain as a good example to consider. It is to be noted it is of fair size, simple in design, and presenting few of those lines and furrows that go to make the human brain so complicated an organ. Its general appearance, however, and its coarse structure are the same. Ou