382 



PROr. M. WATSON AND DR. A. H. YOUNG ON 



tendon, which is joined by the long slender tendon of the outer head. The 

 single tendon thus formed passes down as far as the metacarpo-phalan- 

 geal articulation, where it divides into two parts, each of which, after per- 

 forating the corresponding tendon of the flexor sublimis, is prolonged to 

 the terminal phalanx of an anterior toe. 



Muscles of the Hind Limb : Gluteal Begion. 



Long Vastus is a large muscular mass which arises from the middle line 

 of the sacrum posteriorly, from the upper border of the ischium, and by a 

 strong tendon from the tuberosity immediately below that border. The fibres 

 pass outwards and downwards, the anterior ending on a special tendon 

 which is inserted into the outer border of the patella, blending with the 

 insertion of the extensor mass, whilst the remaining fibres end on a strong 

 aponeurosis which covers the upper half of the external muscles of the leg. 



Superficial Gluteus arises from the outer surface of the iliac bone, 

 reaching as far back as the sciatic foramen, from a strong aponeurosis 

 covering the muscle, and from the fascia lumborum ; the fibres pass almost 

 directly backwards and converge to be inserted into the upper and poste- 

 rior borders, as well as into the outer surface of the great trochanter of the 

 femur. 



Deep Gluteus. — This muscle lies under cover of the preceding, and is bi- 

 laminar, the two laminae being united along their inferior borders, but sepa- 

 rated posteriorly where the sciatic nerve passes between them. The super- 

 ficial part arises from the external surface of the iliac bone, the deeper 

 portion from the outer surface of the ihum in front of the sciatic notch, 

 from a fibrous membrane which covers the notch, and also from the great 

 sciatic ligament. The fibi es from both laminee converge, and are inserted 

 into the anterior surface of the great trochanter, as well as into the adjacent 

 part of the shaft of the femur. 



It will be observed that we have only described two glutei muscles. The 

 bilaminar character of the deeper of these indicates its probable homology 

 with the two deeper glutei muscles usually described in the horse ; or it 

 may be that they correspond only to the deepest gluteus, which in the 

 Ruminants is described by Chauveauas being divided into two portions, each 

 of which is referred to by Rigot as a distinct and separate muscle. 



Obturator Internus arises from the whole of the ischio-pubic portion 

 of the pelvic wall and from the inner surface of the obturator membrane. 

 The fibres pass obliquely forwards and upwards, and the tendon of the 

 muscle escaping from the pelvis through the small sciatic notch, is joined 

 by the fibres of the gemellus, and is ultimately inserted into a deep pit on 

 the inner side of the great trochanter of the femur. 



Gemelli. — These muscles are conjoined, and form a single concave muscu- 

 lar mass, in the concavity of which the extra-pelvic portion of the obtu- 

 rator internus muscle lies. The muscle takes i ts origin from the border of 



