252 THE MYOLOGY OF THE EAVEN. 



perforatus medius primus pedis, which here arises by two 

 slips, an outer tendinous one, from the external condyle 

 of the femur, which has a common origin with other 

 muscles there arising, and is intimately connected with 

 the dense fascia about the front of the knee-joint ; while 

 the second slip arises from between the femoral condyles, 

 in common with other flexors that come off from that 

 point. The two heads are quite independent, but merge 

 with each other before they terminate in their common 

 tendon at the lower third of the tibial shaft. 



" It passes through the tibial cartilage, overlain by, 

 but in close company with, the far more diminutive 

 and narrower tendon of the flexor perforatus annularis 

 primus pedis. 



" When it arrives under the basal phalanx of the 

 median toe, the outer one of the anterior pair, it bifur- 

 cates to -allow the other two flexor tendons to pass, while 

 the slips thus formed become attached to the sides of the 

 shaft of this joint close to its distal head. 



" It will at once be seen that Geococcyx calif or nianus, 

 in common with the vast majority of birds, has no special 

 tendon devoted to the flexing of the second or prebasal 

 phalanx of the fourth toe (here the reversed one). 

 Provision is made for this in various ways in different 

 birds. Here, in the subject before us, a special slip is 

 thrown off for attachment from the deep flexor tendon 

 as it passes over the prebasal joint in question, which 

 slip virtually fulfils the function of a fl.exor perforatus 

 annularis secundus pedis, did such a muscle with an 

 independent tendon exist. 



"The flexor perforatus medius secundus pedis, as in 

 all of the birds I have examined, is one of the best 

 developed perforated tendons at the back of the leg. Its 

 fascia of origin merges with the enveloping fascia about 



