:216 OUTLINES OF EQUINE ANATOJIY. 



PART VIII.— SPECIAL ANATOMY. 



The Abdomen. 



The operator commences by dissecting tbe skin down- 

 wards from tlie middle tlioracic incision towards the middle 

 line of tbe abdomen. Thus he exposes the panniculus, ex- 

 tending over the lateral part of the belly from the external 

 surface of the shoulder. Infero-anteriorly is situated ])ec- 

 toralis magnus, which is superiorly slightly covered by 

 panniculus ; it is about five inches wide, and covers about 

 one third of the length of the under surface of the belly. 

 Posteriorly the panniculus divides into two layers, one of 

 which covers the outer surface of the quarter, the other 

 runs to the inner surface and, as these two layers are in- 

 timately connected, a somewhat tense sheath is formed, 

 which is superiorly attached to the antero -inferior spinous 

 process of the ilium, inferiorly around the patella. It blends 

 posteriorly with the faschia of the quarter. It is the por- 

 tion of panniculus extending to this sheath in the ox, which, 

 covered by skin, foiins that thin fold termed by butchers 

 " the flank." Below this is the superficial abdominal 

 faschia, a smooth yellow layer formed of elastic tissue which 

 is immediately subcutaneous. It is widely spread over the 

 aponeurotic expansions of the abdominal muscles as far 

 forwards as the ensiform cartilage, backwards as the sym- 

 physis pubis. Thick towards the linea alba, gradually 

 grows thinner on approaching the muscular portion of 

 obliquus abdominis externus, and at the postero-inferior 

 part sends a process which, in the male, combines with that 

 -of the opposite side, forming the suspensory ligament of the 

 ^eniSfi-a. thefemale the elastic divestment which covers themam- 

 mary gland, and which sends trabeculae inwards to separate 

 its lobes. Internally this layer is attached to the external 

 oblique abdominal muscle, externally it affords attachment 

 to pectoralis magnus anteriorly, posteriorly it becomes 

 inflected to the internal surface of the thigh* 



