THE LIMBS OF THE HORSE 153 



dorsalis lateralis) is small, and may be absent. When present, it is 

 a satellite of the like-named artery. There is often a small middle 

 dorsal metatarsal vein (v. metatarsea dorsalis media) that joins either 

 the medial dorsal metatarsal or the saphenous vein. 



The lateral superficial plantar metatarsal vein (v. metatarsea plan- 

 taris superficialis lateralis) begins at the venous arch, ascends along 

 the lateral border of the deep flexor tendon in front of the plantar 

 nerve, and is continued as the recurrent tibial vein. A medial 

 superficial plantar metatarsal vein (v. metatarsea plantaris superfici- 

 alis medialis) may be present, but, if so, is very small. It follows 

 the medial border of the deep flexor tendon, and joins either the 

 lateral superficial or the deep plantar metatarsal vein. 



M. extensor digitorum longus. 



A. diyitalis plantaris 

 medialis. 



M. interusseus.. 

 V. digitalis medialis. - 



N. plantaris medialis. 



Third metatarsal bone. 



A. digitalis plantaris 

 ^ lateralis. 



II. interosseus. 



V. digitalis lateralis. 



N. plantaris lateralis. 



.M. flexor digitorum 

 profundus. 



M. plantaris. 

 Fio. 107. — Section across the Metatarsus at the Level indicated by X in Fig. 81. 



The deep plantar metatarsal vein (v. metatarsea plantaris profunda 

 medialis) begins at the venous arch, passes between the two limbs of 

 the interosseous muscle, and ascends between this structure and the 

 third metatarsal bone, to be continued as the perforating tarsal vein 

 (v. tarsea perforans), which pierces the tarsus along with the homonymous 

 artery. 



Near the proximal end of the metatarsus the deep and lateral 

 superficial plantar veins are connected by a transverse branch, and thus 

 the deep plantar arch (arcus plantaris profundus) is formed. 



The Femoro-patellar and femoro-tibial articulations (articulatio 

 genu). — These two articulations, taken together, correspond to the knee- 

 joint of man, and, in the horse, are generally referred to by the collective 

 name of the " stifle-join^y -^^^gu^y^Jjgji^^ation of the bony surfaces 



