As in other branches of the medical and nonmedical sciences, competent investigators have collected and published contradictory data on the physiology of hearing. To evaluate all data from the standpoint of truth or probability is more difficult for me than for the workers in the field who themselves are in disagreement. With the natural implication of this warning and with due regard to the limitation of time, I shall attempt to give an account of the newer (and some of the older) work on the physiology of hearing.
COMPARATIVE PHYSIOLOGY OF AUDITION
It would seem proper to state that man, birds and some of the higher mammals alone hear, since the first can give a greater or lesser account of the sensation and the latter are capable of being trained to certain sounds. As for the rest of the vertebrates and invertebrates, one can say only that sounds