594 



STRUCTURE OF BASILAR MEMBRANE. [sect. 234. 



in dilute caustic soda and potass, and destroyed also by moderately 

 diluted hydrochloric acid. Acetic acid of moderate strength causes 

 these fibres, in the ox, to swell up at once and to become granular 

 in their interior, and then quickly dissolves them ; it has the same 

 action in the Cortian fibres of the cat, but more slowly. Alcohol, 

 ether, chromic acid, concentrated solutions of salt or sugar, cause 

 the fibres to shrink, and when water is then added they swell up 

 somewhat ; these substances, however, have certainly a less harm- 

 ful influence on the structures in question than on the rods of" 

 the retina, and the fibres may be preserved for a long time in 

 them ; this, however, we know to be the case even with the very 

 delicate rods of the retina, especially in careful chromic acid pre- 

 parations, and furnishes no proof of the greater resistance of the 

 Cortian fibres, as has been assumed by several modern writers. In 

 considering the nature of the fibres of Cord, the fact is not with- 

 out significance, that they occasionally exhibit varicosities (see my 

 Micr. Anat.y ii., 2, fig. 435, 3), so that a delicate envelope and 

 darker contents may be distinguished in them. — Besides these 

 fibres, the organ of Corti possesses some other remarkable struc- 

 tures, the chief of which are the ' pedunculated cells ' of Corti, and 

 a special apparatus discovered by myself (see Micr. Anat., ii., 2, 



p. 756), which I will call the 

 lamina reticularis cochlea. 

 This last has been strangely 

 overlooked by all recent 

 writers with the exception 

 of Schultze, although it is 

 to be seen in almost every 

 cochlea, and often in mere 

 fragments of it ; it is, how- 

 ever, in the accurate study 

 of its arrangement, one of 

 the most difficult parts of 

 the organ to investigate. 

 This is not the place to 

 describe this apparatus in 

 much detail, so that I shall 

 refer to a drawing of it, made 

 from a very excellent preparation (fig. 244), and shall only men- 

 tion briefly its component parts. These are — 1. A short trans- 

 parent plate (<?), w T ith delicately defined partitions, corresponding in 

 number to the inner Cortian fibres. This plate is attached to the line 



Fig. 244. 



Lamina reticularis cochlea (mihi). From the ox; 

 magnified 350 diameters, a. outer ends of the inner 

 Cortian fibres (Coins articnlaires internes, Corti) ; b. 

 hegmninp of the outer Cortian fibres (Coins artieu- 

 laires externcs, Corti), seen through the lamina reti- 

 cularis ; c. an outer Cortian fibre ; d. end of the same 

 with the nucleated swelling ; e. transparent plate of 

 the lamina reticularis ; f. straight rod ; g. inner arti- 

 culating segment ; h. outer articulating segment ; i, 

 terminal segment; k. foramina of the first ; /. of the 

 second ; in. of the third row. The great delicacy and 

 elegance of these structures is only partially rendered 

 in this drawiug. 



