108 OF THE MUSCLES. 



also answer the purpose of ligaments, holding the bones 

 firmly together. These, however, are only sought by the 

 matured student — and even by him are seldom made out. 

 They may be considered as altogether unfitted for those into 

 whose hands the present work is intended to pass. 



THE POSTERIOR EXTREMITY. 



Tensor VAGINA (PZa^e II. g-). Origin. From the anterior 

 spine of the ilium. Insertion. Into the small external tro- 

 chanter of the femur ; into the fascia of the haunch ; and 

 into the patella. Action. To advance the leg ; by drawing 

 forw^ards the femur, and upwards the patella ; as w^ell as to 

 render tense the fascia of the haunch. 



Gluteus externus {Plate II. 7i). Origin. From the 

 second spine of the sacrum, and from the anterior spine of 

 the ilium. Insertion. Into the small external trochanter of 

 the femur; and into the fascia covering the gluteus maximus. 

 Action. To draw^ the femur forw^ard ; and to brace the fascia 

 covering the gluteus maximus. 



Triceps abductor femoris (Plate II. o). Originates 

 from the second and third sacral spines. Insertions. Ante- 

 rior head. Into the outer side of the patella. Middle head. 

 Into the aponeurosis, wdiich connects it with the other two 

 heads ; into the tibial fascia ; and into the superior of the 

 tibia. Posterior head. Into the outer side of the gastrocne- 

 mius tendon ; and into the fascia of the tibial region. 



By releasing from the point of origin, the following 

 additional attachments to this muscle wall be discovered : — 



Additional origins. From the second, third, fourth, and 

 fifth transverse processes of the sacrum ; from the transverse 

 process of the first coccygis ; from the sacro sciatic liga- 

 ment ; from the great trochanter ; from the tuberosity of 

 the ischium ; and from the posterior of the small external 

 trochanter of the femur. A bursa will be found between 

 the tendon of this muscle and the great trochanter. 



Action. To steady the body ; and raise the anterior of 

 the sacrum ; when the feet are firmly fixed, as in leaping. 

 The three heads do not simultaneously contract ; but 

 this powerful muscle is in motion, abducting and retracting 

 the limb the whole time during progression. It is also 

 energetically used in kicking. 



Gluteus maximus {Plate II. m) . Origins. From the sur- 



