CHAI-. v.] THE (WTH MUSCLES. 103 



None of the muscles, liowcvcr, ■wliicli i^o to the digits arise from 

 the femur, except the extensor lougus digitorum pedis, Avhile, on the 

 contrary, some of the Hexors and extensors- — as the liexor brevis and 

 the extensor brevis — take origin not in the leg but in the foot 

 itself. 



As to the NUMTiER OF I\IUSCLES ■SVIIIf'TI MAY BE IXSKJITED INTO 



A SINGLE DIGIT, "SVC soc that the ideal perfection of having both a 

 flexor and an extensor inserted into every segment I'rom the meta- 

 tarsal to the last phalanx is only nearly attained in the digitus 

 minimus. Thus its metatarsal is flexed by the pcroneus brevis and 

 extended by the ])eroneus tertius. Its first phalanx is flexed by the 

 interosseus, and is more or less extended by (though it receives no 

 tendon from) the extensor brevis. The second phalanx is flexed 

 by the flexor brevis or perforatus, and is extended by the extensor 

 digitorum longus. The third phalanx is flexed by the perforans or 

 flexor longus, and more or less imperfectly by the interosseous and 

 lumbrical muscle. 



Besides these muscles the digitus minimus has also an abductor 

 and an opponens. 



§ 11. The DIFFERENCES bctwccn the muscles of the fore and hind 

 limbs arc the following : — The flexors and extensors of the pelvic 

 limb arise lower down than do those of the thoracic limb. Nothing 

 in the fore limb answers to the peroneus longus of the hind 

 limb, while nothing in the leg answers to the supinator longus or 

 to the extcnsores carpi radialis longior and brevior of the arm. 

 In the fore-paw there is no acccssorius, and its perforated muscle 

 is a long one, while in the hind-paw it is a short muscle. There 

 is a second (short) extensor of the digits in the hind-paw, there is 

 none in the fore-paw. There is no long extensor tendon to the index 

 and fourth digits of the hind-paw^ The deep flexor tendons spring 

 from one tendon in the fore-paw, from the conjoined tendons of 

 two muscles in the hind-paw. 



In the foot, the hallux being a mere rudiment, it has not muscles 

 corresponding with those wdiich the poUex has. Again, the hind-paw 

 has that very peculiar muscle — the accessorius — to which nothing 

 in the fore-paw appears to correspond. 



The AGREEMENTS between the muscles of the two limbs may 

 be expressed as follows : — The supra and infra-spinatus and teres 

 minor are inserted into the pre-axial tuberosity, while the psoas 

 and ihacus are inserted into the pre-axial trochanter. The sub- 

 scapularis and teres major are inserted into the post-axial tuberosity, 

 the glutei are inserted into the post-axial trochanter. 



The triceps is the great extensor of the arm and the quadriceps 

 of the leg. The biceps of the arm seems to be represented by the 

 gracilis and sartorius of the leg. The coraco-bracliialis corresponds 

 with the adductor ; the extensor ossis metacarpi pollicis with the 

 tibialis anticus ; the flexor carpi ulnaris with the peroneus brevis, 

 and possibly also with the soleus and the gastrocnemius; the 

 extensor carpi ulnaris with the peroneus tertius ; the flexor carpi 



M 2 



