192 ELEMENTARY BIOLOGY. [XIII. 



c. The pectoral region; part of its hard parts in the 

 middle line, only covered by tendinous tissue : 

 external to this, muscles running towards the 

 shoulder-j oint. 



d. The muscles of the throat; small and with a 

 general direction from the lower jaw towards the 

 sternum and shoulder-girdle. 



2. Raise the tissues of the body-wall with a pair of 

 forceps and carefully divide them, a little to the right 

 of the median line, so as to open the body-cavity 

 without injuring its contents; prolong the incision 

 from the pelvis to the posterior end of the breast- 

 bone ; make a transverse incision close to the pelvis 

 and throw back the flap on each side : on the deep 

 side of the left flap will be seen a large vein (anterior 

 abdominal). 



Seize the posterior border of the sternum with 

 a pair of forceps and raise it up : on looking beneath 

 it several fibrous bands will be seen running from it 

 and the hard parts in front of it to subjacent parts ; 

 carefully divide these : then, with a strong pair of 

 scissors, cut through the hard parts in the median 

 line, being very careful not to injure the organs 

 beneath them ; turn each half outwards and pin it in 

 that position ; stretch out each fore-limb to its fullest 

 extent and fasten it with pins. 



3. Note the smooth moist membrane (pleuroperitoneum) 

 lining the inside of the body-cavity and covering the 

 outside of the contained viscera. 



4. The liver will be readily recognized as a great 

 brownish mass covering a great part of the other 

 abdominal viscera: lying in a cleft in its anterior border 



