336 ZOOTOMY. 



covering the turbinals : that on the ethmo-turbinals is dis- 

 tinguished as the olfactory mucous membrane. 



368. The olfactory nerves, given off from the olfactory 

 lobes to the olfactory mucous membrane : the maxilo- 

 turbinals are supplied by the maxillary nerves. 



XLVII. Pass a probe from the anterior nostril into the 

 nasal chamber as far backwards as it will go : 

 remove the turbinals and as much of the maxilla 

 and palatine as is necessary to show 



369. The backward continuation of the nasal chamber to 

 the posterior nares. 



370. The aperture of the Eustachian tube {eu), in 

 the dorsal wall of the posterior nasal passage, a little anterior 

 to the posterior nares : a probe should be passed through 

 the tube from its aperture in the tympanum (§ 351). 



371. The septum nasi {m.etJi^, § 59), forming a median 

 vertical partition between the anterior part of the two nasal 

 chambers. 



372. Jacobson's cartilage {ja, § 60), lying immediately external 

 to the ventral edge of the septum nasi and ensheathed by the palatine 

 process of the premaxilla : it has the form of a cylinder with 

 tapering ends. 



373. Jacobson's organ, seen by carefully removing the palatine 

 process of the premaxilla and Jacobson's cartilage : it consists of a deli- 

 cate tube of mucous membrane, inclosed in the scroll-like Jacobson's 

 cartilage, and opening at its anterior end into the nasal chamber. It is 

 supplied by branches of the olfactory nerve which pass downwards and 

 forwards along the surface of the septum nasi. 



XLVIII. Remove the larynx with the anterior part of the trachea, 

 and dissect away the muscles, &c., attaching them to suvroimd- 

 ing parts. If only one larynx is to be had, make a longitudinal 

 vertical section of it, keep one half entire, and from the other 

 dissect a\Nay the muscles and mucous membrane so as to see 

 the cartilages clearly. If two specimens are to be had, clean 

 the cartilages of one, and use the other for the soft parts, 

 making a longitudinal section of it when necessary (at § 379).' 



