90 STRUCTURE AND CLASSIFICATION OF BIRDS 



Flexor Digiti III, — Arises from metacarpal III^ and is 

 inserted on to basis of phalanx I. of same digit. 



Flexor Metacarpi Badialis. — This muscle arises from the 

 outer condj'le and is inserted on to the ulnar border of 

 metacarpal II. or on to the beginning of metacarpal III. 



Muscles of the Hind Limb 



Sartorius} — This is a broad strap-shaped muscle arising 

 from the ilium and from the fascia covering the glutseus 

 maximus ; it is inserted on to the ligament containing the 

 patella, and on to the crest of the tibia. The muscle has an 

 origin which sometimes extends further forwards, and is 

 then overlapped by the latissimus dorsi. Sometimes, on 

 the other hand, its insertion moves further back. In 

 Phoenicopterus the muscle is divided into three distinct 

 portions. 



GlutcBus Maximus} — This often large muscle was used 

 by Gaeeod ' in his muscular classificatory scheme, and at 

 first termed the tensor fasciae. It has an origin which is 

 sometimes entirely in front of the acetabulum, and some- 

 times extends behind it. It arises tendinously from the 

 fascia covering the gluteus medius, and from the ridge of 

 the ihum; its insertion is tendinous on to fascia covering 

 thigh. 



GlutcBUs Anterior.'^ — This muscle arises from the ridge of 

 the ilium below the last, by which it is entirely covered ; it 

 is inserted by a tendon on to the outer face of the thigh. 

 The most remarkable modification which this muscle under- 

 goes is its entire conversion into tendon in Bucorvus, &c., 

 in which birds it comes to be merely a thigh ligament. 



GlutcBus Medius.^ — This arises fleshily from the ilium, 

 and is inserted by a short strong tendon on to head of 

 femur. 



' 'Ilio-tibialisintemus' (Gadow). ^ ' Ilio-tibialis externus ' (Gadow). 



' ' On certain Muscles of the Thigh of Birds,' &o., P. Z. S. 1873, p. 626, and 

 1874, p. 111. 



■' ' Ilio-femoralis externus ' (Gadow). 



° ' Ilio-trochanterious medius et posterior ' (Gadow). 



