VARIETIES IX THE ARTERIES OF THE LOWER EXTREMITY. 363 



border of the foot between the abductor pollicis and flexor brevis 

 digitorum muscles, supplying the inner border of the foot and 

 great toe. 



The External plantar artery, much larger than the internal, passes 

 obliquely outwards between the first and second layers of the plantar 

 muscles, to the fifth metatarsal space. It then turns horizontally in- 

 wards between the second and third layers, to the first metatarsal 

 space, where it inosculates with the communicating branch from the 

 dorsalis pedis. The horizontal portion of the artery describes a slight 

 curve, having the convexity forwards ; this is the plantar arch. 



Branches. The branches of the external plantar artery are the 



Muscular, 



Articular, 



Digital, anterior perforating, 



Posterior perforating. 



The Muscular branches are distributed to the muscles in the sole of 

 the foot. 



The Articular branches supply the ligaments of the articulations of 

 the tarsus, and their synovial membranes. 



The Digital branches are four in number : the first is distributed to 

 the outer side of the little toe ; the three others pass forwards to the 

 cleft between the toes and divide into collateral branches, which sup- 

 ply the adjacent sides of the three external toes, and the outer side 

 of the second. At the bifurcation of the toes, a small branch is sent 

 upwards from each digital artery, to inosculate with the interosse- 

 ous branches of the metatarsea; these are the anterior perforating 

 arteries. 



The Posterior perforating are three small branches which pass 

 upwards between the heads of the three external dorsal interossei 

 muscles to inosculate with the arch formed by the metatarsea 

 artery. 



Varieties in the Arteries of the lower Extremity. The femoral 

 artery occasionally divides at Poupart's ligament into two branches, 

 and sometimes into three ; the former is an instance of the high 

 division of the profunda artery ; and in a case of the latter kind which 

 occurred during my dissections, the branches were the profunda, the 

 superficial femoral, and internal circumflex artery. Dr. Quain, in his 

 " Elements of Anatomy," records an instance of a high division of the 

 femoral arter} r , in which the two vessels became again united in the 

 popliteal region. The point of origin of the profunda artery varies 

 considerably in different subjects, being sometimes nearer to and some- 

 times farther from Poupart's ligament, but more frequently the former. 

 The branches of the popliteal artery are very liable to variety in size ; 

 and in all these cases the compensating principle, so constant in the 

 vascular system, is strikingly manifested. When the anterior tibial is 

 of small size, the peroneal is large ; and, in place of dividing into two 



