ORGAN OF CORTI. 

 Fig. 328. 



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Fig. 328. A, from a specimen prepared in chloride of gold, showing 

 the three rows of the external hair cells of the Dog in situ, after the 

 removal of the lamina reticularis, and of the membrana basilaris, with 

 the phalangeal and basilar processes, magnified 300 diameters. B, Ex- 

 ternal hair cells (twin-cells) of Vesperugo noctula, magnified 800 

 diameters : a, basilar process (the phalangeal process not visible) ; c, 

 upper nucleus, with claw ; d, lower nucleus ; e, fine fibril (nerve). 

 C, Three external hair cells still connected with the basilar membrane, 

 from Vesperugo noctula : a d c e, as in B ; at c, some fine hairs are still 

 preserved ; at ci, the nucleus is absent, and a conical process, probably 

 a portion of protoplasm, projects beyond it ; 6, phalangeal process ; 

 /, fragment of the membrana basilaris. Z), Two external hair cells 

 from a woman aged 23, magnified 800 diameters : lettering as before ; 

 c, dark spot (? nucleus), the nature of which cannot be determined 

 with certainty ; c,, superior nucleus, with nucleolus which in the hair 

 cells is always remarkably small. The phalangiform process, b, of 

 these cells is torn away, and the remains have retracted towards the 



