X PRACTICAT. niRECTIONS 527 



removed together with the skin ; and in the aduk female, the inainmary 

 glands (p. 489) : trace the main ducts of some of these to their apertures 

 on the teats. 



2. In the necli : — a, the trachea and larynx (p. 489), to see which 

 and the following structures clearly the cervical portion of the cutaneous 

 muscle should be dissected away and the underlying parts carefully 

 separated with a seeker ; b, the hyoid bone, situated in a mass of muscle 

 just anterior to the larynx ; c, the submaxillary glands (p. 495) ; and d, 

 iheXsiXge external jugular veins (p. 509). 



3. In the thorax ; — a, the sternum and xiphisternum ; h, the small 

 clavicles (p. 483) ; c, the pectoral muscles ; d, the vertebral and sternal 

 portions of the ribs and the external intercostal fnuscles : and e, the 

 blood-vessels and nerves going to the fore-limbs. 



4. In the abdomen : — a, the muscles of the abdominal wall, separated 

 in the middle ventral line by a whitish, fibrous band ; b, Poupart' s 

 ligament (p. 489) ; c, the blood-vessels and nerves passing beneatli 

 Poupart's ligament to the hind-limbs. 



II. On the same day on which the animal is killed, remove the skin 

 from the dorsal surface of the head and anterior part of the neck, and 

 remove the muscles covering the anterior cervical vertebrce. A 

 membrane between the skull and first vertebra will then be exposed : rut 

 throughthis, and part of the .r/wra/^wv/ will be seen. With the bone-forceps 

 cut away the arches of the first three or four vertebrie and the roof of 

 the skull — taking particular care in the auditory region — so as to expose 

 the brain : note the olfactory lobes, cerebral hemispheres, cerebellum, and 

 medulla oblongata, and also the dura mater and pia nmter. Then cut 

 through the spinal cord about a quarter of an inch iDeyond its junction 

 with the brain, lever up the latter with the handle of a scalpel, and 

 caiefuUy cut through all the nerves arising from it and separate it 

 from the cranial walls, working from behind forwards. Dissect away 

 the olfactory lobes from their attachments, remove the entire brain and 

 place it in 3 per cent, formaline. 



The animal may be preserved from day to day by wrapping a cloth 

 round it soaked in 3 per cent, formaline 01 strong methylated spirit, 

 and placing it in a closed vessel. 



n. Dissection of the abdomen. 



I. Once more pin the animal down, ventral side uppermost, and 

 make an incision along the middle line of the abdominal muscles from 



