5.^6 TITK RABIilT n\\\\ 



noting Lhc rclraclor (ntlhl nuiNcIe around the lattL-r. (For \\\k slrucUirc 

 of 1 1 10 eye, see y. 538.) Cut ofi" ihe pinna, and ck-ar away the muscles, 

 i^c, cnvcring the tympanic bi:)nc : remove the entire lymjianic and 

 [K-riotic liones (|>. 475) in une piece, la)' upe~n the external auditory 

 passage, and \eiy carefully and gradually cut away the Duler wall of 

 lioth tubular and hulhous portions of the tympanic with the hone- 

 finxeps. Note :-- 



1. The fyinpam't- nicmhraiic \\w<\ (lie handle of ihe malleus ; and after 

 cutting away the former .so as not to injure the latter, and removing 

 rather more of the bulla, make out — 



2. 'I'he Iviiipaiiic cavily ; the i/ial/ciis, ifirus^ and slii/vs ; the tcnso) 

 tyiiipaui and stapedius iiiusch-s ; and the aperture of the Eustachian 

 tulh\ Remove the auditory ossicles, noting as you do so the fenestra 

 oT'dlLs and /e/!es/ra }vtun<la. :i\\<\ examine ihem under the low power 

 of the microscope : by cutting through the periotic with the bone 

 forceps, the position of the )iieiiihyauous labyrinth with the cochlea may 

 be made out. 



III. Dissect ofi' the muscles covering the mandible on the side you 

 are working ; detach its ascending portion from the muscles inserted on 

 to its inner surface, remove it entire, cutting through the symphysis, 

 and clear away the underlying muscles. I'ass a probe from the cut end 

 of the gullet forwards into the mouth: lay open the gullet along this, 

 and pull the tongue downwards, so as to get a view into the interior of 

 the mouth (Fig. 125). Note :^ 



1. a. The palate and velum palali ; h, the loui^-ue and its papilhe 

 (p. 492); 1, the pharynx : d, the i^iottis and epi^'-lottis ; e, the con- 

 tinuation of the pharynx above the velum palati {/rasiy-pharynx), whh 

 which the internal nostrils communicate ; /, the positions of the /eeth 

 (incisors and grinders) ; ^^, the apertures of the naso-palaiine canals 

 (p. 490). 



Then remove the nasal, premaxilla, and maxilla of the same side, 

 x\iA\x\2^\\\Q olfactory nerves and the iurhinals ; and after passing a probe 

 backw'ards from the externa! nostril into the nasal chamber as far as 

 it will go, remove the turbinals on this side, so as to expose the 

 cartilaginous ;/(Z.f(7/yf////w. Also cut away all the remaining bone on 

 the same side of the middle line, slit up the naso-pharynx, and reduce 

 your dissection to a neat longitudinal section, noting — 



2. T\\t cranial cavity, the roof of which will have been cut away if 

 the brain has been removed. 



