THE RABBIT. 



349 



posterior to the origin of the pronator teres, and passing 

 into a long tendon which is inserted into the proximal end 

 of the second metacarpal : the insertion is best seen at a 

 later stage : cut through and reflect. 



423. The flexor profundus digitorum, or flexor 

 perforans (fl.p.d), a large muscle, the chief flexor of the 

 digits, and made up by the union of four heads — 



{a). The superficial head arises from the inner con- 

 dyle of the humerus just posterior to the origin of the flexor 

 carpi radialis, and in common with thepalmaris (§ 424) : cut 

 it through near its origin and reflect. 



{b). The ulnar head lies deeper than and anterior to 

 the foregoing, by the reflection of which it is exposed : it 

 arises from the inner condyle of the humerus in common 

 with the flexor sublimis (§ 425). 



(<r). The radial head arises from the proximal part of 

 the posterior surface of the radius. 



{d). The middle head arises from the posterior surface 

 of the ulna. The four heads unite at the distal end of the 

 fore-arm to form a common tendon, the insertion of which 

 is best seen at a later stage of the, dissection (§ 427). 



424. The palmaris (//), a small, slender muscle arising 

 with the superficial head of the deep flexor from the inner 

 condyle of the humerus and passing into a long tendon 

 which becomes lost in the palmar fascia, or sheet of 

 connective tissue covering the ventral surface of the manus, 

 sending off also a small slip which is inserted into the 

 ungual phalanx of the pollex : cut through and reflect. 



425. The flexor sublimis digitorum {fl.s.d), or flexor 

 perforatus, lying immediately beneath the superficial head 

 of the flexor profundus : it arises in common with the ulnar 

 head of the latter from the inner condyle of the humerus, 

 and divides distally into four tendons, which pass, superficial 



