Page:Popular Science Monthly Volume 1.djvu/367

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attitude. The first turn, particularly when the lesion is old, is slower and less regular; the second is rapid and spasmodic. The first is the consequence of the lesion, the second is the consequence of the regular action of all the nervous centres; and, the better to express this thought,

Fig. 6.

Duck, wounded in the Right Side of the Cerebellum

we may say that, in an animal from which have been taken only the cerebral lobes, we might obtain a movement of rotation if, as soon as the animal is on his fore-feet, we turn him on his back; external interference would replace in this case the action produced by lesion of the pons Varolii.