WITH TWELVE FIGUXES
T h e eventual object of the experiments reported in the following paper was the rearing of some tadpoles which had been deprived of their auditory vesicle and acoustic ganglion, either on one side alone or on both sides; that is to say, an artificial production of a unilateral and bilateral absence of the acoustic apparatus. This was done in the expectation that it might be possible to trace the central acoustic path, in this new way, and perhaps throw further 'Read in part before the Section of Anatomy of the British Medical Association, at the meeting held in Toronto, August 21-25, 1906.
For experimental work on fishes we are for the most part indebted to Lee ('93 and '98) and Lyon ('m), both of whom carried on their experiments at the Woods Hole Laboratories. Further work on fishes has just been completed at the same place by Professor Parker, whose paper I am told is now in press and will appear in the Bulletin of the U. S. Fisheries Bureau. An abstract of part of his work was read before the American Zoological Society (Parker, '05). A voluminous literature exists concerning experiments on higher vertebrates, particularly the pigeon, but it need not be considered here.