"If the cerebellum be removed gradually by successive slices - an operation easily done in a pigeon - there is a progressive effect on locomotive actions. On taking away only the upper layer there is some weakness and a hesitation in gait. When the sections have reached the middle of the organ the animal staggers much, and assists itself by its wings in walking. The sections being continued further, it is no longer able to preserve its equilibrium without the assistance of its wings and tail ; its attempts to fly or walk resemble the fruitless attempts of a nestling, and the slightest touch knocks it over. At last, when the whole cerebellum is removed, it cannot support itself even with the aid of its wings and tail ; it makes violent efforts to rise, but only rolls up and down ; then, fatigued with struggling, it remains for a few seconds at rest on its back or abdomen, and then again commences its vain struggles to rise and walk. Yet all the while sight and hearing are perfect. See fig. 26. It attempts to escape, and appears to have all its sensations perfect. The results contrast very strongly with those of removing the cerebral lobes. "Take two pigeons," says Longet ; "from one remove completely the cerebral lobes, and from the other only half the cerebellum ; the next day the first will be firm on its feet, the second will exhibit the unsteady and uncertain gait of drunkenness.""
(from Professor J. G. M'Kendrick, M.D.'s fascinating contribution to the article PHYSIOLOGY, volume XIX of the 9th Edition of Encyclopaedia Britannica, 1885.)