64 PROFESSOR OWEN ON THE AYE-AYE. 



The tendon of the fasciculus representing the /ea;or longus pollicis has an adhesion 

 to the supplementary carpal ossicle and attached part of the transverse fascia, beyond 

 which adhesion (PI. XXII. fig. 1, 3< °) it sends the more distinct tendon to the poUex ; 

 but the effect of this attachment is to oppose, not the pollex only, but the pad at its 

 outer base, which is supported by the supplemental ossicle (PI. XXI. fig. 17, o) in the 

 grasping act, when the radial is opposed to the ulnar side of the hand. The fleshy part 

 of both flexors, but especially of the deeper-seated muscles, continues far on towards the 

 hand, as in other Lemuridte, and also as in the climbing Rodentia, thus enabling the 

 muscles to continue their action as finger-benders in the bent position of the hand itself. 

 The tendons of the deeper flexors are thicker than those of the superficial flexors ; but 

 both those of the middle digit are very slender. 



The pronator quadratus rises from the fore part of the lower fourth of the ulna. Its 

 fibres pass obliquely outwards and downwards, to be inserted into the corresponding fore 

 part of the radius. Both the pollex and minimus have their abductor and adductor 

 muscles and short flexors. The tendons of the deep flexors give attachment to four 

 lumbricales. Some of these minor muscles of the digits are noticed in the descrip- 

 tion of the Plates. 



Muscles of the loiver limbs. — The psoasmagnus (PI. XXIV. fig. 1, i) presents a character 

 of unusual length, corresponding with that of the lumbar region, from which it chiefly 

 arises, its highest or foremost origin being from the last dorsal vertebra. An inner 

 and superficial portion (a) may be recognized as an ill-defined psoas parvus, but 

 becomes distinct below where it is inserted into the ileo-pectineal ridge. An outer por- 

 tion (b) more especially unites itself with the iliacus internus, and, with the main body 

 of the psoas, passes on to be inserted into the lesser trochanter, the unusual prominence 

 of which relates mainly to the power of this great flexor of the trunk on the thighs and 

 reciprocally. 



The iliacus internus (ib. 2) is a long and thin or flat muscle from the fore part of the 

 ilium, behind and exterior to the psoas, with which, especially the outer fasciculus, 

 it unites below, for a similar insertion in the lesser trochanter. 



The tensor vagina femoris (Pis. XXIV. & XXV. fig. 1,3) is represented by a small 

 external fasciculus from the anterior superior spine of the ilium, which extends into the 

 fascia covering the fore and outer part of the thigh. 



The sartorius (Pis. XXIV. & XXV. 15) is a long, flat, rather broad muscle, arising 

 fleshy between the iliacus internus and ecto-gluteus^ from the anterior border of the 

 ilium, passing obliquely across the inner side of the thigh, slightly expanding to be 

 attached to about an inch of the upper part of the spine of the tibia (PI. XXV. fig. 2, 15) 

 and to a thin fascia covering the knee-joint (PI. XXIV. /). 



The gracilis {ib. ") rises fleshy from the whole of the symphysis pubis, and is similar 



' Vrolik, op. cit. p. 45. 



' Gluteus maxirmis of Anihro-potomj. (See 'Osteology of Chimpanzees,' &c., p. 15.) 



