Figs. 185 and 186. Transverse Sections through the Leg at the begin- 

 ning of the middle third and near the ankle. 



Frozen Sections. 



The Fasciae (blue) in Fig. 185, shew that on the Anterior aspect of the 

 limb, the Extensor Group of Muscles arise from fascia; on the Posterior aspect 

 from the Fascia enveloping the limb, and forming a special canal for the Short 

 Saphenous Vein ; the particular Fasciae of the Muscles are represented. 



At a higher level this Fascia is continuous on the flexor aspect with 

 muscular attachments: on the outer side, with tlie expansion of the Biceps Tendon 

 internalh' with the expansion of the Sartorius, Gracilis and Semitendinosus Tendons. 



The circumference of the leg diminishes below the middle as the muscles 

 become tendinous, thus near the ankle there are practical^ only tendons and bones. 



In the subcutaneous tissue, the Long Saphenous Vein on the inner, and 

 the Short Saphenous Vein on the posterior surface are observed. The Fascia, 

 which is a continuation of the Fascia Lata, is only interrupted by the Anterior 

 Surface of the Tibia as it becomes intimtitely blended with the Periosteum. On 

 the Antero-external aspect the Fascia sends a septum to the Fibula, which sepa- 

 rates the Peroneal Muscles from the Extensors. A deep la3'er passes transversely 

 across from the Posterior Siu-face of the Tibia to the outer surface of the Fascia, 

 this layer lies deep to the Soleus and Gastrocnemius Muscles, which it separates 

 from the still more deeply situated Flexors. Above the ankle this layer is very 

 strong and binds the Flexors down to the Bone; the Tendo Achillis becomes 

 more prominent near the Os Calcis. The space formed in this way is filled by 

 large pads of fat. The Internal Surface of the Tibia is palpable throughout its 

 whole extent being only covered by skin and thin superficial fascia. The other 

 surfaces of this triangular prism of bone are covered b}' muscles. The Fibula is 

 completely surrounded by muscles except the Head and a triangular surface above 

 the External Malleolus which are subcutaneous. 



The bond of union between the Tibia and Fibula is very firm. The upper 

 Tibio-Fibular Articulation allows of scarcely anj' movement; this joint may com- 

 municate with the Bursa under the Popliteus Muscle and indirectly with the Knee- 

 joint. Lower down these two bones are held together by a very strong Interosseous 

 Membrane, whereas in the lower tliird, the union is 3'et more firm. 



Near the ankle, so firmly are these bones held together, that they may 

 be viewed as one while the Inferior Tibio-Fibular Articulation is rather to be con- 

 sidered as an excavation of the Ankle-joint, than as an independent joint. 



In the upper third of the leg, of the 2 most important vessels which require 

 ligation, the Anterior Tibial Artery is easily found on the Posterior Surface of 

 tlie Posterior Tibial Muscle in the Neuro- Vascular Bundle ; external to this is the 

 Peroneal Arterv. 



