458 TOPOGRAPHICAL ANATOMY. 



d. Nerv. peronceus, on the inner side ofra. biceps, covered only 

 by fascia, on the posterior surface of condyl. extern, femor. to the 

 outer side of condyl. extern, tibice, as far as behind capitul. fibula. 



The two nerves (c and d) receive the art. and vein in the centre 

 between them. 



4. M. poplitceus, 5. Ligam. poplit&um, pass obliquely down- 

 wards from condyl. extern, femoris to condyl. intern, tibice. 6. 

 Fossa condylorum posterior of the knee joint. 



Situation of the Viscera, relative Position of the Organs in 

 the Three Great Cavities. 



708. Cranial Cavity. 



After removing the cranial bones we directly come to 

 I. Dura mater, from the internal surface of which the follow- 

 ing processes pass between the recesses of the brain : 



1. Proc.falciformis major, s.falx cerebri. Its superior convex 

 border extends from foram. caecum and crista galli of ethmoid 

 bone along the crista frontal, interna, beneath the central line of 

 the cranial arch as far as protuberant, occipital, interna ; contain- 

 ing the sinus longitudinal, superior. Its inferior concave border 

 is extended freely between the two hemispheres of the cerebrum, 

 close above the corp. callosum in the scissura longitudinal, cerebri; 

 it contains the sinus longit. inferior. 



2. Tentorium cerebelli ; lies over the fossa cranii inferior, trans- 

 versely between the lobes of the cerebrum and the superior surface 

 of the cerebellum, below thefalx cerebri and above thefalx cerebelli. 

 In the middle line passes sinus quartus [straight or horizontal 

 sinus]. Its external convex border is attached to the linece cruciatce 

 transverse occipitis, the angulus super, oss. petrosi, as far as the 

 proc. clinoidei poster.; contains sinus transvers. and petrosi supe- 

 riores. Its free, internal, concave border reaches as far as the 

 corp. quadrigemina, splenium corp. callosum and pons Varolii. 



3. Process, falciformis minors, falx cerebelli lies in theincisura 

 cerebelli poster., between the hemisphcer. cerebelli, behind tuber 

 valvul. and pyramis vermis, beneath the centre of the Tentorium, 

 and extends along the crista occipital, interna from the protuberan- 

 tia as far as foram. magnum ; containing, at the posterior attached 

 border, sinus occipitalis posterior. 



4. Process, spurii durce matris are visible after the brain is re- 

 moved from the skull. 



a. Roof of the sella turcica, stretched between proc. clinoid. 



