180 SPECIAL ANATOMY. 



cuboid, to the dorsal surface and tubercul. metatarsi 5. Use : 

 extends and draws the foot outwards ; abducts somewhat the 

 little toe. 



Nerves for 5. to G.: peronaus. 



C. On the posterior surface, 

 a. Superficial layer. 



372. 7. Gastrocnemius s. gemelli surse. 



Pos. : above, by its two heads, it bounds the popliteal region, 

 forms the posterior thick flesh of the calf, close under the skin ; 

 the external head covered by biceps, the internal by semitendinos. 

 Or. : 1. The external head from condylus femor . extern, (gemell. 

 extern.} 2. The internal head from condylus intern, (gemellus 

 intern, stronger.) Both heads unite in the form of the letter V. 

 Ins. : tendo Jlchillis (to tuber calcanei). Use : to extend the foot, 

 rather flexing the leg. 



373. 8. Plantaris (in man rudimentary, often wanting). 

 Pos. : above and to the inner side of the external head of the 



last muscle passing between soleus and gemell. intern. Its long 

 tendon first between Gastroc. and Soleus lies on the inner side 

 of tendo ^chillis. Or. : condylus externus femoris (from cap- 

 sular ligament), connected with gemell. extern. Ins.: tuber 

 calcanei (before or close to the tend. Achill.). 



374. 9. Soleus. 



Pos. : covered, particularly, by gemell. intern, behind ; before 

 by flex, digit commun. and hallucis propr., tibial postic., Vasa 

 and Nn. tibial. postic. and Jibulares. Or.: 1. tibisR lin. obliq. 

 poster, (under poplitseus). 2. Capitul.fibulse (posterior surface). 

 Ins. : tendo Jlchillis. This arises from the junction of the ten- 

 dons of 7., 8., and 9.; is one and a half to two inches long, is 

 fixed broad to the posterior surface of tuberc. calcanei, and lies 

 in a double sheath ; the external is thick and red, the internal, 

 thin, colourless, and more tense. Use: 7. to 9. extend the foot; 

 8. extends, in the lower animals, the fascia plantaris. 



b. Deep layer. 



375. 10. Poplitseus. 



Pos. : small, thin, triangular, oblique from without, downwards 

 and inwards upon the knee joint, covered by plantaris and gas~ 

 trocnemius, separated by Vasa poplit. and n. poplit. intern 

 Or.: fossa behind [at the side of] condyl. extern, femoris (under 

 m. gemellus. extern.). Ins.: the triangular, posterior (and supe- 



