48 LANDMARKS MEDICAL AND SURGICAL. 



(102). The incision to reach the artery in this part of its 

 course would fall in with the outer border of the sartorius. 



To command the femoral artery in Hunter's canal, the 

 pressure should be directed outwardly, so as to press the 

 vessel against the bone. 



THE BUTTOCKS. 



103. Buttocks. Bony landmarks. The bony land- 

 marks of the buttocks which can be distinctly felt are : I, 

 the posterior superior spines of the ilia ; 2, the spines of the 

 sacral vertebrae ; 3, the two tubercles of the last sacral ver- 

 tebra ; 4, the apex of the coccyx in the deep groove leading 

 to the anus ; 5, the tuberosities of the ischia on each side of 

 the anus. 



The posterior spines of the ilia are about the level of the 

 second sacral spine, and correspond with the middle of the 

 sacro-iliac symphysis. 



The third sacral spine marks the lowest level to which 

 the membranes of the cord and the cerebro-spinal fluid 

 descend in the spinal canal. 



The tuberosities of the ischia, in the erect position, are 

 covered by the gluteus maximus. In the sitting position 

 they support the weight of the body, and are only covered 

 by a thick pad of coarse fat Between this pad and the bones 

 there is a bursa, which becomes occasionally enlarged and 

 inflamed in coachmen. 



The prominence of the nates is one of the characteristics 

 of man in connection with his erect attitude. ' Les fesses 

 n'appartiennent qu'a 1'espece humaine.' They are formed of 

 an accumulation of fat over the great muscle of the buttock 

 (gluteus maximus). From their appearance we may gather 

 some indication of the state of the constitution. They are 

 firm and globose in the vigorous ; loose and flaccid in the 

 infirm. Wasting and flattening of. one, compared with the 

 other, is an early symptom of disease in the hip. 



104. Fold of the buttock. The deep furrow, termed 



