. In the above figures, A shows some nerve cells of dilTerent shapes. I> shows a stellate cell from a developing animal, magnified 400 diameters. When a cerebro-spinal nerve is irritated by pinching, there is either pain manifested, or there is twitching of one or more muscles, to which the nerve distributes its fibres. From various considerations, it is certain that pain is- always the result of change in the nerve cells of the brain. Therefore, in such experiments as those referred to, it seems to the experimenter that the irritation of the nerve-fibre is conducted in one of two direction
. In the above figures, A shows some nerve cells of dilTerent shapes. I> shows a stellate cell from a developing animal, magnified 400 diameters. When a cerebro-spinal nerve is irritated by pinching, there is either pain manifested, or there is twitching of one or more muscles, to which the nerve distributes its fibres. From various considerations, it is certain that pain is- always the result of change in the nerve cells of the brain. Therefore, in such experiments as those referred to, it seems to the experimenter that the irritation of the nerve-fibre is conducted in one of two directions, either ta the brain the central termination of the fibre, when there is pain, or to a muscle when there is movement. The effects of these simple experiments arc the types of what always occur, when nerve-fibres are engaged in the performance of their functions (Kirke). The brain of the horse and of the other higher animals is formed of a central white part composed of fibres, and an outer convoluted portion of grey matter composed of nerve-cells and fibres. In the horse it weighs about 23 ounces, in the ass 12 ounces; and it is formed of a front portion called the cerebrum, and a hind part called the
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Keywords: ., bo, bookcentury1800, booksubjecthorses, booksubjecthorsesdiseases
