82 



IX. — Oy TBX AItoloCtT of the Oeaxg UiAyG. Ey "William Selby 

 Chiircli. B.A., Lee's Eeader in Anatomy, Ckrist Ctiureli, Oxford. 



(Cmitinued from Xat. Skt. Bev.j'or 1S61, page 516.) 



The Flexor Long^us PoUieis appeared at first si^lit to be a portion 

 of the Flexor Profundus, but its origin Tras distinct, as it arose from 

 the radius, and remained distinct from the Flexor Profundus through- 

 out its whole course. It went to the index only in the Orang ; and, as 

 it passed through the annular ligament, it sent off a slip to the tendon 

 of the Flexor Profundus. The tendon of this muscle was supplied 

 with a Liirnhricalis muscle, inserted as in man; each of the branches 

 of the Flexor Profundus were also suppHed with a good-sized Lum- 

 hricalis muscle. In the Gorilla, the Pie.ror Longus Pollicis sends a 

 small tendon to the thumb, though the mass of the muscle has there 

 become a flexor of the index. (Duvemoy. 1. c. p. 106.) In the ]Magot 

 and Cebus, these muscles become fused on the palm of the hand, 

 forming as it were a common Flexor Profundus. In the Magot. the 

 radial portion, or Flexor Pollicis. went chiefly to the iudex, and a 

 slip from the ulnar portion, or Flexor Profundus, snpplied the chief 

 portion of the tendon going to the pollex. In the Cehus, the same 

 ftision of the muscles toot place : but the radial portion was much 

 the stronger, and supplied the thumb with a tolerably strong tendon, 

 as well as the index and middle fingers, the ulnar portion supplying 

 the third, fourth and fifth digits with tendons. 



The arrangements of the Lumhricales in these ^lonkevs was 

 peculiar. They formed a fleshy mass on the palmar surface of the 

 fused tendons : the first and second arose together from the tendon 

 of the index, and partly from that of the third digit and the slip 

 supplying the thumb : the third and fourth arose together from the 

 tendons of the third and fourth digits. They were all inserted on 

 the radial side of the first phalanx of the fingers. 



Yesalius* states that the Flexor Long^is Pollicis is present in the 

 tailless apes, but that it is only a branch from the Flexor Profundus 

 in. the tailed ones. 



The Flexor Suilimis is subject to many slight variations in man, 

 but in these Monkeys it presented almost the same appearance that it 

 normally does. The Flexor Profundus frequently has a distinct head 

 coming from the internal condyle of the humerus, and fusing with 

 the Test of the muscle lower down. (Theile.+) The Flexor Longus 

 Pollicis has been noticed double ; one part going to the thumb as 

 usual, the other joining that tendon of the Flexor Profundus, which 

 supplies the index. fTheHe.*) And a more frequent anomaly is the 

 presence of a second head from the internal condyle of the humerus, 

 or the receipt of fibres from the Flexor Profundus or the Suilimis, 

 which would appear to parallel the fusion of the Flexor Pollicis 

 and Profundus met with in the bulk of the Quadrumana. Mr. 



* Vol. i. p. 254, t Encv. Anat. torn, iii. p. 246. ± Ditto, p. 249, 



