XIII.] THE FBOG. 19 



b. It will be seen tliat the two auricles contrac 

 together; immediately after them, the ventricle 

 and then, instantly, the bulbus arteriosus. 



c. Kaise the ventricle so as to see the venous sinus 

 note that it contracts immediately before th 

 auricles. 



6. The parts exposed by the preceding dissection 

 (B. 1. 2). 



Draw them carefully without disturbing them. 



a. The throat-muscles: through the broad thin muj 

 cle in front (mylo-hyoic[) is seen the hypoglossc 

 nerve. 



h. The larynx: forming a hard prominence in th 

 middle line, just in front of the aortic arches. 



c. The heart and aortic arches (see B. 5. i.) : th 

 three terminal branches of the latter, viz. — 



a. The carotid trunk; the anterior division ; end 

 ingin a small reddish body (the carotid gland), 



/S. The systemic aortic arch. 

 J. The puhno-cutaneous artery: the hindmos 

 branch. 



d. The liver: a great brown two-lobed mass; it 

 left lobe the larger and subdivided into two. 



e. The lungs : the posterior ends of these may b 

 seen as sacculated pouches, one on each side of th 

 liver, but they are frequently not visible unti 

 the latter organ has been removed. 



f. The stomach: a small portion of this is see: 

 projecting beyond the lower left border of th 

 liver. 



13—2 



