154 



Hand. Foot. 1 



Flexor of first metacarpal (-tarsal) Obsolete, Tibialis posticus. 



Extensor of first „ Extensor carpi radialis Tibialis anticus. 



accessorius, ~~ 



Flexor of second „ Flexor carpi radialis, Tibialis secundi (Huxley). 



Extensor of second „ Extensor carpi radialis Tibialis anticus of Agonti. 



longior, Tibialis anticus secundus of Echidna. 



Flexor of third „ Flexor carpi radialis Obsolete ; sometimes a slip of peroneus longus. 

 brevis (Wood). 



Extensor of third „ Extensor carpi radialis Obsolete, 

 brevis. 



Flexor of fourth „ Slip of flexor carpi Peroneus longus, slip of. 

 ulnaris. 



Extensor of fourth ,, Obsolete. 



Flexor of fifth ,, Flexor carpi ulnaris, Peroneus longus. 



Extensor of fifth ; , Extensor carpi ulnaris, Peroneus brevis. 



and its continued slip, „ Ulnaris quinti, Peroneus quinti. 



The muscles in italics are either common anomalies in man, or 

 muscles in lower animals. 



The second class of muscles which we have to consider are the 

 pronator and supinator series — a group specially developed in those 

 cases in which the forearm bones rotate the one upon the other : of 

 these we find typically two long and four short muscles in each limb. 

 The first of these is the supinator longus type, represented in the lower 

 limb by the outer head of the gastrocnemius, which resembles the 

 former in being attached to the ridge above the outer condyle of the 

 femur, and in constituting the outer lip of the popliteal space, the 

 homotype of the anticubital fossa. The second or condyloid origin of 

 the pronator teres corresponds with the last-named, and is represented 

 in the lower extremity by the inner head of the gastrocnemius : both 

 these muscles have lost their typical insertion in the lower limb, as 

 there is no independent motion of the one bone upon the other. There 

 are four shorter transverse, or nearly transverse muscles, which should 

 act typically — the two anterior as pronators, the two posterior as 

 supinators ; of these, the upper anterior one is the slip so peculiarly 

 human, the coronoid origin of the pronator radii teres, whose nature I 

 have explained in the ''Journal of Anatomy," K S., vol. i., p. 8, and 

 this has its dorsal antithetic in the supinator brevis — a muscle whose 

 course is the direct counterpart of the former on the dorsal aspect. 

 These two are represented in a modified form in the lower limb of man, 

 the first as the tibial origin of solseus (loc. cii. supra y p. 8), and the 

 second as the popliteus. Among the many resemblances between the 

 supinator brevis and popliteus, I may here state that, as in the tendon of 

 the latter a sesamoid cartilage has been described as a rare occurrence 

 in man, although a typical condition in other animals ; even so, in 

 the origin of the former a distinct sesamoid bone existed in the 

 extremity of one subject which I have dissected. The second pair 

 of transverse muscles we find represented anteriorly by the prona- 

 tor quadratus, which finds its homotype in the peroneo-calcanean 

 muscle above described : the dorsal antithesis of this muscle is usually 

 the subject of the same variety of modification as is always presented by 

 the last-named — that is, its tendon is continued to seek a metacarpal 

 site of insertion, and in the forearm, being specialized to perform a 



