Physiology of the “Stick” in the Dry Picking of Poultry

(Continued from April issue.)

To summarize the above results there are eight instances where the cerebellum was severely cut with no effect upon the feathers and only two instances where injury to the cerebellum loosened the feathers. On the other hand, there are seven instances where injury to the medulla alone loosened the feathers and no instance through the entire course of the experiments where even the slightest injury to the medulla failed to loosen the feathers. Thus it is practically certain that there is a brain center controlling the feather muscles and that this center is in the medulla.

This fact was further corroborated by means of electric stimuli on five pigeons. The cerebellum and medulla of No. 10 were exposed and the cerebellum electrically stimulated with no effect upon the feathers; the medulla was then stimulated, causing a marked loosening of the feathers lasting some time after the . . .