No. I.] THE VERTEBRATE EAR. 



279 



graft the nose of a fish upon the auditory nerve, and determine 

 if the fish may not be able to hear through the mediation of the 

 hair cells of the nasal epitheliicm, — a feasible operation, which 

 promises valuable information to the successful operator. The 

 grafting of the ear upon the nasal nerve would in all probability 

 not be a success, on account of the protected condition of the 

 sensory cells. This protected condition of the auditory hair 

 cells may be in part due to an attempted exclusion of all sensory 

 impulses, save those of vibratory motion of the water ; at any 

 rate, such exclusion follows as a consequence of the inclosure 

 of the organ. 



Foster (1891, 92), loc. cit. p. 1213 : "If the organ of Corti is 

 the means by which we appreciate tones, it is evident that by 

 it also we must be able to estimate loudness, /(?r tJie gnality of a 

 musical sound is dependent on the relative intensity, as ivell as 07i 

 the nature, of the overtones [italics mine]. And since noise is 

 at best but confused music, the cochlea must be a means of 

 appreciating noises as well as sounds. But this would leave 

 nothing whatever for the rest of the labyrinth to do in respect 

 to the appreciation of sound, save so far as the difference in 

 structure between the hair cells of Corti, with their short thick 

 rods, and the hair-bearing structures in the maculae and cristse, 

 with their thin delicate hairs, may possibly indicate a difference 

 of function, the latter being more susceptible to the irregular 

 vibrations of noises." 



The physiological role of the utricular sense organs is very 

 inadequately understood, but owing to the priraitiveness of the 

 histological characters of the sensory plate and its entire agree- 

 ment in structural details with the ampullar sensory epithelium, 

 it is probable that they retain their primitive function ; at least 

 such a view is allowable until it is shown that the function has 

 changed more than the apparent structure. I have nothing to 

 add to what has been written on this subject by Hasse, Hensen, 

 Meyer, and Retzius, except to offer the view that the otoliths 

 do not play so important a part in the function of this sensory 

 apparatus as has been commonly held, and to insist upon the 

 proper allowance being made for the increasing refinement and 

 sensitiveness to given stimuli that the auditory nuclei of the 

 brain must undergo in connection with the ever-growing asso- 

 ciation mechanism. Granting this fact its full and proper influ- 



