CHAP. IV] THE GENERAL ANATOMY OF THE TARSII 109 



pectineus are concentrated at the upper end of the bone. The 

 M. gluteus tnedius, M. gluteus minimus, and the M. tensor fasciae 

 femoris are described by Burmeister. 



The M. biceps femoris is most remarkable in appearance, con- 

 sisting as it does of a very long thin tendon leading from the 

 ischium downwards to a broad muscular sheet. This tendon is 

 stated by Klaatsch 1 to be recognizable in other forms, though 

 embedded in the upper end of the muscle-mass. In Tarsius it is 

 exposed, and with the great sciatic nerve it lies in a groove 

 between the M. gluteus maximus and the M. adductor magnus. 

 There is no short bicipital head, nor is the M. tenuissimus present. 



The M. gracilis and semitendinosus are also peculiar, for 

 though distinct and ribbon-like above, they share a thin cord-like 

 tendon of insertion into the tibia. The M. quadriceps extensor 

 cruris is remarkable for the great development of the MM. vasti, 

 especially the M. vastus lateralis (externus). This is doubtless 

 related to the leaping movements so characteristic of Tarsius. 



Below the knee-joint, the M. tibialis anticus first calls for 

 remark in view of its great size, another token of the saltatory 

 capabilities of Tarsius (cf. Vallois, op. cit. 1912). The M. tibialis 

 posticus is comparatively small, yet it is attached to the tibia and 

 fibula as well as to the interosseous membrane. Its long slender 

 tendon widens out below the ankle, and runs distinctly to the 

 navicular bone (and, in the specimen dissected by me, to the 

 sheath of the M. abductor minimi digiti as well). The M. soleus 

 has a circumscribed origin from the fibula only. 



The M. plantaris arises from the femur, and its tendon passes 

 over the os calcis to form the plantar aponeurosis. This is supple- 

 mented by an additional band for the hallux, and from the margin 

 of this part a few fibres are contributed to the M. abductor hallucis. 



The plantar muscles and tendons will now be described in the 

 same order as was adopted in the account of the Lemur. 



(i) M. flexor digitorum pedis brevis. This muscle has two 

 modes of origin, viz. : 



(a) From the deep aspect of the plantar aponeurosis, 

 which contributes the tendon to digit No. 2 only. 



1 Morphologischex Jahrbuch, Band xxix. 1902, p. 264. 



