No. 3-] AUDITORY OR HAIR-CELLS OF THE EAR. 449 



body of the enlargement. These bodies occur with considerable 

 regularity, so that in surface preparations of the organ of Corti 

 and, better still, in horizontal sections of the same, a row of the 

 inner hair-cells is accompanied by a row of these large 

 varicosities. I am undecided what their true nature is. 

 One is not able with this method to determine their 

 cellular nature, and I have no observations on this point 

 by means of other methods which it is desirable to publish 

 now. 



A point of importance I shall mention here, though it does 

 not belong strictly to the nerve endings. As I have already 

 stated, the hairs on the acoustic cells of the cochlea seldom 

 show in well stained preparations, though they frequently do in 

 those incompletely stained. This is due to the shortness of 

 the ends left on the cell caps, and the enclosure of these 

 short ends by the silver deposit. In the case of the maculae 

 and cristae the hairs do not as a rule break off, and when they 

 do they leave a relatively large and long conical hair remnant 

 which is not covered by the silver precipitate to such an extent 

 as to hide the nature of the process. The hairs of the maculae 

 and cristae are very well defined bv this method, and appear 

 about twice as long as by the ordinary methods of staining with 

 balsam mount. The relation of these hairs to the otoliths I 

 shall describe in another communication.^ 



Returning to the hair cells, we find that the nerve processes 

 which leave them are not always simple, but often branching 

 threads as the Golgi stain shows them. The branches anasto- 



1 In Fig. 24, PL III, I have sketched the stained hairs of a portion of the organ 

 of Corti in a 20 cm. pig embryo. First of all one will notice that the hairs are not 

 arranged in the form of a horseshoe upon the top of the cell, but they cover a 

 more or less regular and approximately circular area. Between the row of dots 

 marked i (inner hair-cells) and the row marked 2 is found the crest of the Cortian 

 arches. The following rows are quite complete throughout all parts of the cochlea 

 until we arrive at the fifth row which occurs for short distances only along the 

 middle spiral turn and the distal and proximal parts of the basal and apical turns 

 respectively. Golgi's method brings out the presence of these hairs with a clear- 

 ness of definition shown by no other method. It may be noted in passing that the 

 caps of the supporting cells are not in the region of the fifth row sufficiently well 

 developed to form the figures composing the " reticulate membrane." PI. II, Fig. 

 15, shows the appearance presented by an isolated hair-cell defined among the 

 stained rows of hairs. 



