SECT. 235.] ORGAN OF SMELL. 6oi 



pensably necessary, and are best got from animals quite newly killed ; when 

 it is desired to see the parts in a perfectly normal state, serum or a solution of 

 sugar must be employed for moistening them; chromic acid preparations, 

 too, are very proper for many purposes. Further, the successful examination 

 depends upon a certain dexterity in exposing and detaching the delicate 

 parts with which we have to deal ; and much patience will be required, 

 because it must frequently be left to accident whether a certain arrangement 

 comes into view or not. In order to see the nervous plexuses of the zona 

 ossea of the cochlea, this structure must be deprived of its calcareous salts 

 by diluted hydrochloric acid, while, on the other hand, the ganglion-cells of 

 this locality must be sought by careful breaking up of the osseous zone in a 

 medium which has no chemical action on the parts. Perpendicular sections 

 are important, and are to be obtained either from isolated laminae spirales 

 taken out of chromic acid preparations and treated with hydrochloric acid, or 

 In >m whole cochlea) treated in this manner. Or we may lay the cochlea first 

 in a bed of glue, and then make sections of the lamina spiralis. 



Literature.— E. Huschke, in Fror. Not., 1832, No. 707 ; Iris, 1833, Nos. 18, 

 34 ; K. Steifexsaxd, in Muller's Archiv., 1835 ; S. Pappenheim, Die spcciclle 

 Gerveoelehre des GeJiororgans, Breslau, 1840, and Fror. Not., 1839, Nos. 131, 

 19+ and 195 ; G. Breschet, Recherches sur VOrgane de V Ouie dans THommc 

 et les Animaux vertHbres, 2nd edit., Paris, 1 840 ; E. Krieoer, De Otolithis, 

 Berol, 1840; Wharton Jones, The Organ of Hearing, in Todd's Cyclop., 

 vol. ii., 529 ; J. Hyetl, JJeber das innere Gehororgan des Menschen und der 

 Saugethiere, Prag, 1845; A. Corti, in Zcitsehr. f. ?ciss. Zool. iii., p. 109; 

 Reissner, De Auris Interna Formationc, Dorp., 1851 ; E. Harless, Art. 

 Horen, in Wagner's Handw.der PTiysiologie, iv., p. 311, and Milnehn. Gel. 

 Anzeiger, 1851, Nos. 31 and 37 ; Stannius, in Gbtt. Nachrichtvn, 1850, No. 

 16. ibid., 185 1, No. 17; Kolliker, TJeber die letzen Endigungen des Nervas 

 Cochlea and die Fanhtion der Schnecke, Gratulat. an Fr. Tiedejiann, Wurzb., 

 1854; Reissner, in Mull. Arch. 1854, p. 420; Claudius, in Zcitsehr. f m. 

 Zool.™., p. 154; Bottcher, Obs. Micr. de rat. qua Nervus Cochleae termi- 

 natur, Dorp., 1856 ; H. Reich, in A. Ecker's Untcrs. z. Ichthyol., Freib., 1857, 

 p. 24 ; M. Schultze, iii Mull., Arch., 1858, p. 343 ; v. Troltsch, in Zcitsehr. 

 J.tviss. Zool., 1857, ix., p. 91 ; Gerlach, in his Mihr. Studien, 1858, p. 53. — 

 The student of this subject should also compare the systematic works of 

 Krause, Huschke, Arnold, Todd and Bowman, Remak (on development), 

 and myself. 



III. — Of the Organ of Smell. 



§ 235. The olfactory organ consists of the two nasal cavities, 

 supported by bones and cartilages, and lined by a mucous mem- 

 brane, and of a certain number of accessory cavities, viz., the 

 sinus frontales, sphenoidales, ethmoidales, and the antrum Highmori. 

 Of all these spaces, however, only the uppermost parts of the nasal 

 cavities, where the olfactory nerve is distributed, are subservient to 

 the sense of smell itself; for the other spaces are either simple 



