350 ZOOTOMY. 



and post-axial to the tendon of the flexor profundus, into 

 the manus and along the ventral faces of the second to the 

 fifth digits : each tendon divides at the base of the proximal 

 phalanx into two slips which pass one on either side of the 

 proximal phalanx to be inserted into the proximal end of 

 the middle phalanx : cut through and reflect. 



The tendon for the fifth digit has in connection with it a very small 

 muscle, the flexor brevis minimi digiti [Jl.p.d.m.), which arises 

 partly from it, partly from the pisiform bone, and joins the tendon 

 again at its distal end. A similar muscle, the flexor brevis poUicis 

 ( fl.pp.), arises from the annular ligament and is inserted into the tendon 

 of the flexor profundus going to the pollex. 



426. The retinacula {r), transverse tendinous bands 

 which keep the flexor tendons in place : there is one at 

 the metacarpo-phalangeal articulation, formed by an ex- 

 pansion of the tendon of the flexor sublimis, one proximal 

 to the joint between the proximal and middle phalanges, 

 and another distal to the same Joint. 



427. The insertion of the flexor profundus : its tendon 

 spreads out into a broad stout sheath lying immediately 

 dorsal to the tendons of the superficial flexor : from this 

 sheet five tendons are given off, one to each digit, each 

 passing along the ventral face of the digit and being inserted 

 into its ungual phalanx : the tendons of the second to the 

 fifth digits pass between the two slips into which the 

 corresponding tendon of the flexor sublimis is divided. 



428. The lumbricales {lb. i, 2, 3), three small spindle-shaped muscles 

 arising from the ventral surface of the tendon of the flexor profundus 

 at the place where it divides into slips for the second to the fifth digits : 

 they are inserted into the proximal ends of the proximal phalanges 

 on the pre-axial side of the third, fourth, and fifth digits respectively. 



429. The abductor minimi digiti (ab.d^), a small muscle lying on 

 the ventral face of the fifth metacarpal : it arises from the pisiform 

 bone, and its tendon joins with that of the superficial flexor going 

 to the fifth digit. 



