CEREBELLUM
The cerebellum is the second largest division of the brain. The metencephalon gives rise to the cerebellum, which is the reflex center for muscular coordination and refinement of movements.

Injury or removal of the cerebellum can cause impaired muscle coordination. A bird lacking a cerebellum cannot fly and its wings thrash around. When the human cerebellum is injured, any activity necessitating fine motor coordination, such as threading a needle, becomes practically impossible.