1884.] ANATOVIY OF SCOPUS UMBRETTA. 549 



outwards and backwards to be iuserted on to the inner side of the 

 femur just between the origin of the crurceus and vastus internus. 



4. The extensor muscle of the thigh is composed of a number of 

 fused muscles ; it arises from both the inner and outer side of shaft 

 of femur ; it is inserted on to the patella and on to the fascia, 

 covering the knee by a broad flat tendon. 



5. Of the glutseal muscles, the outermost one (glutceus I.) is the 

 largest. Glutaus II., which partly underlies glutceus I., is some- 

 what smaller. Glutceus III. is very small. 



6. The obturator externus is large ; it is covered superiorly by 

 an aponeurosis, which extends back about half way to the posterior 

 extremity. 



7. The obturator internus has an oval origin ; its tendon of 

 attachment is surrounded by a muscular mass which corresponds 

 to the gemelli. 



8. The tensor fascia extends about half way down the thigh ; it 

 originates from the fascia covering glutmis I. 



9. The biceps arises from the whole of the postacetabular ridge 

 of the ilium; it is inserted, as usual, on to the fibula, after passing 

 through a tendinous sling. 



10. The femoro-caudal is a long, slender muscle, with the usual 

 origin and insertion ; the tendons at either end of the muscle are 

 extremely fine. 



The accessory femoro-caudal is quite absent. 



1 1 . The semitendinosus is well developed : it arises from the 

 posterior end of the ilium and from the fascia in the neighbourhood ; 

 it is inserted on to the tendon of the gastrocnemius (see fig. 3) in 

 common with the accessory semitendinosus. 



12. The accessory semitendinosus is moderately large ; it arises by 

 fleshy origin from inferior margin of femur close to its distal extre- 

 mity, and is inserted partly on to the oblique tendon between it and 

 the semitendinosus, and partly on to the tendon which connects the 

 latter with the gastrocnemius. 



13. The semimembranosus is half as broad again as the semiten- 

 dinosus ; it arises from the lower margin of hinder portion of ischium 

 and from a small portion of the pubis posteriorly ; it is inserted by 

 a thin broad tendon on to the inner side of the leg. 



The ambiens is absent. 



14-15. There are two adductor muscles. 



16. The gastrocnemius arises by four distinct heads, which unite 

 about half way down the leg into a broad flat tendon gradually 

 narrowing until its insertion: — (a) The external head arises from 

 the under surface of the femur ; it is tendinous on the inner side, 

 where it fuses with the outer loop of the biceps sling, (b) The 

 second head arises from the femur by a thin flat tendon below the 

 origin of the last, (e) The third head arises from the inner side of 

 the under surface of the femur ; it is fused with the inner of the 

 two adduetor muscles at its origin ; about half way down it receives 

 the tendon of the conjoined semitendinosus and accessory semiten- 

 dinosus. (</) The inner head is the largest ; it arises from the 



