VARIETIES IN THE ARTERIES OF THE LOWER EXTREMITY. 333 



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 be- 

 tween the toes, and divide into collateral branches, which supply 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 interosseous branches of the metatar- 

 sea ; 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 inos- 

 culate 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 some- 

 times into three ; the former is an instance of the high division of the pro- 

 funda artery ; and in a case of the latter kind which occurred during my 

 dissections, the branches were the profunda, the superficial femoral, and 

 the internal circumflex artery. Dr. Quain, in his " Elements of Anatomy," 

 records an instance of a high division of the femoral artery, 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 sometimes 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 terminal branches at the lower third of the leg, 

 descends to the lower part of the interosseous membrane, and emerges 

 upon the front of the ankle, to supply the dorsum of the foot : or the pos- 

 terior tibial and plantar arteries are large, and the external plantar is con- 

 tinued between the heads of the first dorsal interosseous muscle, to be 

 distributed to the dorsal surface of the foot. Sometimes the posterior 

 tibial artery is small and thread-like ; and the peroneal, after descending 

 to the ankle, curves inwards to the inner malleolus, and divides into the 

 two plantar arteries. If, in this case, the posterior tibial be sufficiently 

 large to reach the ankle, it inosculates with the peroneal previously to its 

 division. The internal plantar artery sometimes takes the distribution of 

 the external plantar, which is short and diminutive, and the latter not un- 

 frequently replaces a deficient dorsalis pedis. 



The varieties of arteries are interesting in the practical application of a 

 knowledge of their principal forms to surgical operations ; in their tran- 

 scendental anatomy, as illustrating the normal type of distribution in ani- 

 mals ; or, in many cases, as diverticula permitted by Nature, to teach her 

 observers two important principles : first, in respect to herself, that, how- 

 ever in her means she may indulge in change, the end is never overlooked, 

 and a limb is as surely supplied by a leash of arteries, various in their 



3. The long flexor tendons. 4. The tendon of the peroneus longus. 5. The termination 

 of the posterior tibial artery. 6. The internal plantar. 7. The external plantar artery 

 8. The plantar arch giving off four digital branches, which pass forwards on the ir'er 

 ossei muscles. Three of these arteries are seen dividing, near the heads of the meta 

 tarsal bones, into collateral branches for adjoining toes. 



