PLANTAR ARCH OF VESSELS. 623 



The FLEXOR BREVIS MINIMI DIGITI (fig. 212, c ) is a small narrow 

 muscle on the metatarsal bone of the little toe, and resembles one of the 

 interossei. Arising behind from the metatarsal bone and the sheath of 

 the peroneus longus, it blends with the inferior ligament of the metatarso- 

 phalangeal articulation, and is inserted into the base of the metatarsal 

 phalanx of the toe; it is united also by fleshy fibres with the fore part of 

 the metatarsal bone. 



Action. Firstly it bends the metatarso-phalangeal joint, and nextly it 

 draws down and adducts the fore part of the fifth metatarsal bone. 



Dissection (fig. 213). In order that the deep vessels and nerves may 

 be seen, the flexor brevis and adductor pollicis are to be cut through at 

 the posterior part, and thrown towards the toes ; but the nerves supplying 

 them are to be preserved. Beneath the adductor lie the plantar arch, and 

 the external plantar nerve, with their branches; and in the first interos- 

 seous space is the part of the dorsal artery of the foot that enters the sole. 

 All these vessels and nerves with their branches require careful cleaning. 



The muscles projecting between the metatarsal bones are the interossei ; 

 the fascia covering them should be removed. 



The PLANTAR ARCH (fig. 213, d) is the part of the external plantar 

 artery which reaches from the base of the metatarsal bone of the little toe 

 to the back of the first interosseous space: internally the arch is completed 

 by a communicating branch from the dorsal artery of the foot (e~) (p. 624). 

 It is placed across the tarsal ends of the metatarsal bones, in contact with 

 the interossei, but under the flexor tendons, and the adductor pollicis to 

 which it gives many branches. 



Venae comites lie on the sides of the artery, and the external plantar 

 nerve accompanies it. 



From the front or convexity of the arch the digital branches are sup- 

 plied, and from the opposite side small nutritive branches arise. 



Three small arteries, the posterior perforating, leave the under part: 

 these pass to the dorsum of the foot through the three outer metatarsal 

 spaces, and anastomose with the dorsal interosseous branches of the ante- 

 rior tibial artery. 



The digital branches (c) are four in number, and supply both sides of 

 the three outer toes, and half the next. One to the outer side of the little 

 toe is single; but the others lie over the interossei in the outer three 

 metatarsal spaces, but beneath the transversalis pedis (fig. 212), and bi- 

 furcate in front to supply the contiguous sides of two toes. They give fine 

 offsets (fig. 212) to the interossei, to some lumbricales, and the trans ver- 

 salis pedis; and at the point of division they send small communicating 

 branches anterior perforating, to join the interosseous arteries on the 

 dorsum of the foot. 



The first digital runs on the outer side of the little toe, supplying the 

 flexor brevis minimi cligiti, and distributes small arteries to the teguments 

 of the outer border of the foot. 



The second belongs to the sides of the fifth and fourth toes, and fur- 

 nishes a branch to the outer lumbrical muscle. 



The third is distributed to the contiguous sides of the fourth and third 

 toes, and emits a branch to the third lumbricalis. 



The fourth, or most internal, corresponds with the second interosseous 

 space, and ends like the others on the third and second digits ; it may 

 assist in supplying the third lumbricalis. 



