ioo ELEMENTARY BIOLOGY. [CHAP. 



sternum close to the middle line, and divided 

 into a number of bellies by transverse tendi- 

 nous intersections. 



/?. Other muscles outside the rectus on each 

 side. 



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-joint. 



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. 



