378 H. N. MOSELEY. 



often sufficient. Everything depends on treating the section 

 finally long enough with absolute alcohol before applying the 

 oil of cloves. 



If all the water be not removed from the section the oil of 

 cloves will not penetrate it, and the section will not become 

 properly transparent. 



Sections prepared in this way should show in sitit the gan- 

 glion spirale, the limbus, membrana basilaris and ligamentum 

 spirale, with the bridge of Corti's rods and its accompanying 

 mass of cells, and, at least in some of the turns, the membrane 

 of E-eissner and that of Corti. A cochlea, when once prepared 

 in chromic acid, and transferred to absolute alcohol, may be 

 preserved in this latter for any length of time, aud will be 

 always ready for further preparation. 



For the demonstration of the lamina reticularis and the 

 finer structure of Corti^s rods, the membrana basilaris, &c., 

 osmic acid preparations are the best. To prepare these 

 all that is necessary is to break open the cochlea with fine 

 bone forceps or strong scissors, so as to expose without 

 injury as much of the organ of corti as possible, and place 

 the pieces in a 1 per cent, solution of osmic acid. In 

 from tAvelve to twenty-four hours the organ will be found 

 sufficiently hardened, the nerve-tissue being turned quite 

 black by reduction of the acid. Small portions of Corti's 

 organ may be removed with a fine scalpel or scissors, and 

 examined in glycerine, or mounted in glycerine jelly. If 

 the cochlea made use of has been properly fresh, the lamina 

 reticularis and rods of Corti will be found to be defined in 

 the most striking manner. 



It is hoped that these notes may be of some use to demon- 

 strators of anatomy, &c. It is a pity that preparations of 

 Corti's organ are not more often shown to classes. A great 

 deal has yet to be done in the way of the comparative 

 anatomy of Corti's organ amongst Mammalia, notwith- 

 standing the splendid Avork of Boettcher. The Corti's organ 

 of Marsupials and Monotremes would probably yield inter- 

 esting results, as also perhaps those of Cetacea, seals, and 

 otters, when compared together. Those who wish to go 

 more deeply into the subject should consult for method 

 Boettcher, and also Waldeyer, in the last number of 

 ' Strieker's Handbuch.' I have unfortunately not the books 

 at hand just now, or I would give extracts. Both authors 

 advocate the use of chloride of palladium. Further, two 

 papers have just appeared on the subject of Corti's organ 

 in ' Max Schultze's Archiv,' one by Gottstein, the other by 

 Nuel, 2nd part, 1872. 



