( 39f. ) 



by a flat tendinous bead on to the neck of the femur, being crossed just at its 

 insertion by tlie tendon of the Glntaeus V. 



The Stiperfcial femoro-caudal muscle is a great mass of fiesli immediately 

 underl3nng the biceps ; it springs from the ilium as well as posteriorly from the 

 candal vertebrae. It is inserted along the edge of the femur external to the femoro- 

 caudal, adductor and accessory semitendinosus. It reaches exactly as far as the 

 distal end of the origin of the last mentioned. The muscle, as has been correctly 

 observed by Owen and Garrod, is divided into two parts, separated by the emergence 

 of the sciatic nerve and artery. The anterior smaller part (called by Owen the 

 "Adductor brevis femoris ") is aj)pareutly to be distinguished among other struthious 

 birds and in the tinamous. 



The large extent of the Biceps femoris is not clearly indicated in the figures 

 of either Owen or Garrod. Its origin by a tendinous sheet in common with that 

 of the last-described muscle extends considerably in front of the acetabulum as well 

 as considerably behind it. Before its insertion on to the fibula tLrough the biceps 

 sling it gives off from its upper surface a fibrous band to the outside of the 

 gastrocnemius. This has not been mentioned in Apteryx ; but Gadow states its 

 existence in Struthio. I may remark that I have found a somewhat similat 

 insertion in the rail Podica soiegalensis — a fact which may conceivably be of some 

 little classificatory import. On the other hand Weldon has figured (p. 648, Fig. 3, 

 B) a closely similar arrangement in the duck, and I have observed the same in 

 a swan. 



The Semimembranosus of Apteryx australis is very much as it has been described 

 by Garrod in .1. oweni. It has two very distinct heads of origin, between which 

 arises the femoro-caudal and lies a portion of the oil gland. The posterior part 

 arises close to the semitendinosus from some of the coccygeal vertebrae ; the rest 

 of the muscle springs partly tendinonsly, partly muscularly, from the ischium, and 

 even to a small extent from the pubis ; the two join almost immediately, arching in 

 a crescent-shaped outline over the femoro-candal, as already said. In A. haasti 

 the two heads of the muscle were present, but the discontinuity at their origin was 

 less marked; the second head, moreover, was limited to the ischium, and was 

 circular or thereabouts in section, instead of strap-shaped. The tendon of insertion 

 of the muscle runs side by side with, and is indistinguishable from, that of the 

 semitendinosus. 



Semitendinosns. — This muscle shows a slight variation in the relations of its 

 accessory (femoral) head within the genus. In A. australis the accessory head 

 of the semitendinosus was distinctly separated from, though parallel to, the middle 

 head of the gastrocnemius. In ^1. haasti no such separation is obvious. 



Adductor. — There is but one adductor in Apterijx. It is a flat thin muscle 

 arising from the front edge of the ischium. 



Rectus femoris {= Vastus externus + Criiraeus'). This is an enormously 

 thick and fleshy muscle arising from the greater part of the shaft of the femur from 

 the neck onwards. The vastus externus portion is much the larger, and on the 

 outer side of the thigh forms a continuous and undivided mass of muscle ; on the 

 upper side of the thigh there are indications of its division into two accessory heads 

 of origin. The cruraeus portion from the greater part of the length of the inner side 

 of the femur ends in a strong round tendon, to which many fibres of the vastus 

 externus portion are attached, and which then becomes continuous with the strong 



* Crvraent + gracilit of Owen's deucriptioa of the AjtUryx. 



