VIII.] 



THE MUSCLES. 



may be united with the flexor profundus in one mass, as in 

 the Kangaroo and Echidna. It may also be confined to 

 the hand, and therefore be a short muscle, as in the Iguana 

 and Chameleon. It is small in Birds. 



That symmetrical bifurcation and definite arrangement of 

 the perforated tendons which obtains in man is by no means 



F.C.V 



F.sJ 



-F.-p d 



FIG. 299. FLEXOR MUSCLES AND TENDONS OF FORE-FOOT OF HYRAX. 



Pl t palmaris longus ; Feu, flexor carpi ulnaris ; Fsd, flexor sublimis digitorum ; 

 Ffdy flexor profundis digitorum ; Flp, flexor longus pollicis ; Pf, palmar 

 fascia ; Fbm, flexor brevis manus ; L, lumbricales. 



constant. Thus it is absent in Birds ; and in lower Vertebrates 

 (e.g. Iguana) this muscle can hardly be said to be inserted by 

 definite tendons. Even in man's own order we may see by 

 the Nycticebinae how the index digit may fail to have a true 

 perforated tendon, while the imperfect condition of the flexor 

 sublimis may be supplemented (as in Hyrax) by an extra 



