28 



The perpendicular artery arises at right angles below the mid- 

 dle of the OS suffraginis, descends on the side of the digit, inclines 

 forward and terminates above the coronary band by anastomos- 

 ing (joining) with its fellow, their union forming the superficial 

 coronary arch, which supplies the coronary band with blood. 



The transverse artery is given off under the lateral cartilage, 

 passes forward between the front of bone (os coronce.) and the 

 extensor tendon and joins its fellow, forming the deep coronary 

 arch, supplying the surrounding parts with blood. 



The artery of the frog arises behind the pastern joint at the 

 superior part of the lateral cartilage, enters the sensitive frog 

 and divides into anterior and posterior branches. It supplies 

 the sensitive frog with blood. 



The preplantar uvgiial artery is given off just back of the 

 wing of the os pedis, passes through the notch in the wing and 

 along the preplantar groove in the wall of the bone, at the ante- 

 rior extremity of which it terminates by several branches which 

 enter the os pedis and anastomose with the circulus arteriosus. 

 Before entering the bone two branches are given off which sup- 

 ply the bulbs of the frog and the lateral cartilage with blood. 



The plantar ungual artery is the terminal branch of the dig- 

 ital, passes through \^e plantar foramen on the tendinous surface 

 of the OS pedis and enters the bone within which it joins its fel- 

 low, forming the circulus arteriosus, from which spring ascend- 

 ing and descending branches. The former are the anterior 

 laminals, which leave the bone through numerous openings on 

 its wall, supplying the sensitive laminse with blood; the latter 

 (descending branches) are the inferior communicating arteries, 

 which average 14 in number. They pass through the foraminse 

 (openings) situated just above the edge of the os pedis and unite 

 outside to form the circumflex artery which runs around the 

 toe, giving off ascending branches to the sensitive laminse and 

 about 14 descending ones, the solar arteries, which supply the 

 sensitive sole and unite posteriorly to form the inferior circum- 

 flex artery. 



The veins of the foot are very numerous and arranged in an 

 external and internal (interosseous) network. 



They are valveless, allowing the blood to flow in either direc- 

 tion in sudden emergency. 



