120 THE VOYAGE OF H.M.S. CHALLENGER. 



Muscle No. 5, Meckel, vol. vi. p. 95. 



Fectineus, Owen, p. 40. 



Described by Eeid, p. 144. 



L'accessoire iliaqiii' du fl(kliisseur perfore, Gervais and Alix, p. .3.3. 



Ainbiens, SundevalL 



Attachments. — The ambiens muscle is of large size in the Peuguins. At its origin, 

 which measures an inch in breadth, it is attached to the lower border of the pubic bone, 

 immediately below and behind the acetabulum. The flattened, muscular belly passes 

 along the inner side of the thigh, and immediately above the knee joint ends on a slender 

 tendon, which, after passing from within outwards across the front of the knee joint, 

 where it lies in a groove on the anterior border of the patella, joins that head of the flexor 

 digitorum perforatus which arises from the posterior surface of the lower end of the 

 femur. 



Action. — This muscle extends the hip, and through the flexor perforatus digitorum the 

 ankle joint. By means of its connection with the latter it flexes the knee joint as well 

 as the toes. 



Relations. — The beUy of the muscle is subcutaneous, and lies between the insertion 

 of the adductor maguus internally, and the origins of the gracilis and extensor cruris 

 externally. The tendon of insertion as it crosses the knee joint is concealed by the 

 insertion of the sartorius. 



Nerve siqyply. — A branch from the crural nerve. 



2. Flexor perforatus digiti interni, 



Flechisseur perfore (part of), Vicq d'Azyr, 1774, p. 512, No. 3. 



Der tiefe Beuger des ersten Gliedes der iiuieni Zelie, Wiedemann, p. 105. 



Der tiefe Beuger des ersten GKedes der innern Zche, TiedemauB, p. 344, No. 6. 



Muscle No. 2 (part of), Meckel, vol. vi. p. 117. 



Flechisseur commun perfore, Cuvier, vol. i. p. 396. 



Flexor perforatus (part of), Eeid, p. 144. 



Flexor perfo7-atus digitorum pedis, second (?) portion, Owen, p. 39. 



Flechisseur perfore, eoiiche prrofonde, Gervais and Alix, p. 36. 



Attachments. — This muscle arises from the depression on the posterior surface of 

 the femur above the internal condyle. After being joined by a portion of the tendon 

 of the ambiens muscle, it separates from the common muscular mass about the middle 

 in length of the tibia. The muscular fibres end on a single tendon, which, after 

 passing through a canal in the fibro-cartilage behind the ankle joint, is inserted into the 

 base of the first phalanx of the second (inner) toe. 



Action. — It flexes the second toe. 



