THE ANATOMY OF THE CHIMPANZEE. 37 



anterior surface of the tendon. This is much tlie largest tendon. That of the index 

 arises as a small muscular belly from the coronoid, soon becomes tendinous, and sends a 

 small muscular bundle to the division for the third finger. It then gives off a sei'ies of 

 short oblique fibers, which run to another parallel tendon which is the terminal one. It 

 passes obliquely under the others just above the wrist. The three inner tendons pass 

 under the annular ligament in the same plane, that for the little finger being a shade 

 behind. 



Expressed differently, the condyloid head supplies the fourth and fiftli fingers (the 

 latter receiving a trifling bundle from the radius). The coronoid head goes to the 

 middle finger and index. The radial head goes to the middle finger. 



N. B. A connecting link with the flexor profundus arises as a muscle, perhaps 1-2 

 inch broad and from 5 to 6 inches long, from the coronoid portion. Its tendon becomes 

 the deep tendon of the index and receives on its radial side tlie fibers of the radial 

 portion of the muscle next described. 



Flexor profundus digitorum is very clearly divided into a smaller radial and a 

 larger ulnar part. The former arises from the front of the radius and a little of the inter- 

 osseous membrane; all its fibers go into the connecting link just described, which is the 

 tendon of the index. The ulnar portion (separated from the radial by the anterior 

 interosseous vessels and nerves) divides into three tendons. That for the minimus 

 comes from a muscular ))elly that is distinct nearly half way up the fore-arm. The 

 other two are much more closely connected. The ulnar portion also gives some muscular 

 fibers to the index tendon. 



Flexor longiis jiolUcis has no existence whatever as a muscle. A minute tendon 

 first appears a little above the annular ligament as a thickening of the delicate sheath of 

 the radial part of the flexor profimdus. As it descends it grows stronger, becoming a 

 well-defined little tendon, perhaps 1.5 mm. broad, going to the second phalanx of the 

 thumb. This has been repeatedly seen in the chimpanzee, but usually the tendon comes 

 directly from the muscle. 



There can be, I think, no (question that in this flexor groui) the anthropoids exhibit 

 much individual variation. The accurate comparison ot the different descriptions is 

 more wearisome than profitable, owing to the complication of the structure. The 

 accounts all dift'er more or less. The connecting slip from the superficial flexor to the 

 deep one is not normal in the chimpanzee, but occurs as an anomaly as it does in man. 

 In " Sally " such a slip was found going to the deep tendon of the ring finger. 



Lumbricales are four in number. The first arises from the radial side of the 

 tendon of the index; the second from the other side of this tendon and the radial side of 

 the tendon of the medius. The third springs from the neighboring sides of the tendons 



