CHAP. IV] THE GENERAL ANATOMY OF THE CERCOPITHECIDAE 135 



found in some of the lower Eutheria. But even the M. tenuissimus 

 is not known to exist in the Cercopithecidae. 



The adductor mass of femoral muscles is well developed. The 

 M. adductor longus is large and contains few tendinous fibres. 

 The M. adductor brevis is only to be separated artificially from 

 the M. adductor magnus. The latter is clearly composed of two 

 elements, and the superficial artery passes between them obliquely 

 as it enters the popliteal space. One part of the muscle (supplied 

 by the sciatic nerve) arises close to the tuber ischii and ends at 

 the medial condyle of the femur (pars ischio-condylaris). The 

 remainder (supplied by the obturator nerve), arising from the 

 rami of the ischium and pubis, is inserted into the femoral shaft, 

 and extends over the " popliteal area " of that bone. 



The M. gracilis is wide and strong. Below the knee-joint it is 

 inserted partly into the tibia (entirely so in the Semnopithecidae : 

 Kohlbrugge), and partly into the deep fascia of the leg. The tendon 

 of the M. semitendinosus has a similar (twofold) distribution. 



The M. quadriceps extensor cruris consists of the usual com- 

 ponents. The M. rectus has a large flattened " acetabular " head 

 (the "reflected" head of human anatomy), while the second head 

 is distinct though small in Cynocephalus. The M. vastus lateralis 

 is more extensive about the great trochanter than is the M. vastus 

 medialis. The M. vastus intermedins is closely related to the 

 latter, and gives off no fibres (save possibly a few to its lateral 

 side) to form a M. subcrureus. 



As in the Lemur, the M. soleus in the Cercopithecidae owns a 

 fibular origin only. The M. plantaris sends a long slender tendon 

 downwards between the Mm. gastrocnemii and soleus. This tendon 

 is intimately connected with the tendo Achillis. Yet it can be 

 dissected away from this, without much difficulty. Then it will 

 be found to pass round the heel to become continuous with the 

 plantar fascia. The muscle is reduced in size as compared with 

 that of the Lemur (and of Tarsius 1 ). 



(i) The chief features of the plantar fascia consist (according 

 to Loth 2 ) in the marked development of the "aponeurosis tibialis " 



1 v. the illustrations in Vallois' memoir on Platycnemia, Bulletin de la Soc. 

 (VAnth. de Paris, 1912, p. 274. 



2 Correspondenzblatt der Deutschen Antli. Ges. xxxviii. 1907. 



