;4 



THE RABBIT 



carotid ; \\ith the seeker carefully separate it from the carotid, and trace 

 it forwards to the angle between the head and neck— at whicli point it 

 enlarges to form a gaiiglwn, and backwards to the thorax. Branches are 

 given off to t)ie larynx (antt'rior and posk'rior or recurrent laryngeal 

 nci-vs) and to the heart (depressffr) nerves, but the dissection of these 

 may be omitted by the beginner. 



2. The synipalhetic (Fig. 125), running on the dorsal side of the 

 carotid artery. It is most easily distinguished by seizing the carotid 

 with the small forccjis just at the junction of the head and neck and 

 putting it slightly on the stretch : the vagus ganglion will then be seen 

 on the outer side of the artery, and the more elongated anterior cc>-iical 

 ganglion of the sympathetic on its inner side : trace the .sympathetic 

 nerve from this ganglion backwards to the thorax, at the anterior end 

 of which (close to the subclavian arter)') it enlarges to form \\\<i posterior 

 cervical ganglion^ and then becomes continuous with the thoracic portion 

 of the cord. 



3. The hypoglossal nei'ce will be seen at about the level of the v.agus 

 ganglion, passing forwards to the tongue. 



4. Note — tr, the thyroid gland : b, the thyroid ^Vi(\ cricoid cartilages of 

 the laryn\ ; c, the brachial and vertebral l)ranches of the subclavian 

 artery; and d^ the brachial plexus (]). 515). 



IV. Remove the heart and lungs from the body, together with the 

 posterior end of the trachea and recognisable portions of the aorta, 

 precaval, and postcaval. Fasten out the organs under water with their 

 ventral surftce upj")ermost, and after making out the course of the pul- 

 monary arteries and vein^^ cut throtigh thent close to the lungs and 

 separate the latter from the heart. Note : — 



1. The two main lot^es of each lung and the two aece^^orv loi>cs on the 

 right side. 



2. The cartilages of the trachea and bronchi : trace the bronchi for ii 

 short distance into the lungs. Sketch. 



^'. Cut away the outer walls of both auricles so as to expose their 

 cavities, taking care not to injure the veins which enter them. Wash 

 out the contained clots of blood, and note — 



1. a. The appendix of each auricle, and the network of muscular 

 bands in its walls ; b, the septum aurieularum and fossa ovalls — best 

 seen from the left side by holding the heart belween your e\'es and the 

 light. 



2. ii. The auriculo-ventriiular apertures: b, the apertures of the 



