

600 MR. J. C. GALTON ON THE MYOLOGY OF 





tion. The insertion-tendon of the abductor pollicis longus is also, he observes, " not 



seldom double 



» 1 



Theile makes no mention of the division of the former muscle in Man. 

 Extensor proprius hallucis. — Arises by a flat delicate tendon from about the middle 

 third of the anterior ed<?e or ridsje of the fibula. It then runs obliquely outwards, till it 



~ ~ — — Q 



passes under the strong pulley common to it and the tibialis anticus, when its direction 



is changed to one straight for its proper digit. At the astragalo-scaphoid articulation it 



becomes tendinous ; and the straight continuation of the tendon, after expanding over 



the proximal phalanx of the hallux, terminates at the distal joint of this digit. 



The tendon, moreover, a little posterior to the metatarso-phalangeal articulation, gives 



from its fibular side an offset to join one sent off to meet it from the inner of the common 



extensor tendons, which, after this junction, is continued to the base of the proximal 



phalanx of the second toe, there to join the expansion of the tendon of the extensor 



communis sent to this digit. This arrangement much resembles that which I have 



described and figured as existing in Dasypus, only that there is no pulley attached to the 



accessory ossicle which might serve to change the direction of the tendon of the extensor 

 hallucis. 



Rapp 2 describes the tendon of this muscle in M. tamandua as splitting into two 

 branches, which pass to the first and second digits respectively, the latter of these 

 branches entering also into communication with the tendon of the common extensor. 



Extensor communis digitorum. — Arose by a strong flat tendon from the outer aspect 

 of the external condyle of the femur, being covered by the lateral patellar ligament at 

 this joint. It had scarcely, if any, origin from the tibia and fibula. Its muscular belly 

 had about one-third of the bulk of that of the largely developed tibialis anticus. Just 

 before it gains the dorsum of the foot, the muscle passes under a very strong ligamen- 

 tous loop or pulley, which is attached to the anterior portion of the calcaneum, and, 

 slightly, to the astragalus. Here it contracts, and divides into four equal-sized tendons. 



The arrangement of these tendons, though at first sight somewhat complicated, may, 

 I think, be best simplified thus :— The two innermost were fused together, so as to form 

 a kind of aponeurotic expansion or web on the dorsum of the foot. This compound 

 factor may be conveniently termed the " tibial " division. The " fibular " division was 

 formed by a similar fusion of the two outermost tendons ; and both " tibial " and 

 " fibular " divisions had, moreover, a slight communication with each other. 



The tendons, though thus fused together, may, however, each be traced with a consi- 

 derable degree of certainty to its proper destination. 



The first tendon, beginning from the tibial side, sent a branch to join that of the 



extensor hallucis ; but the main portion was continued straight to the terminal phalanx 



of the second digit, expanding, however, over the metatarso-phalangeal articulation of 

 this digit. 



The second tendon passed to the tibial side of the tendinous expansion over the meta- 

 tarso-phalangeal joint of the middle digit, and was also continued to the terminal 

 phalanx. The expansion was joined on its fibular side by the inner of the two branches 









1 Muskellehre, pp. 211 and 276. 



Op 



