819 



5261. The left tibia. 



The distal end and a great part of the shaft are tumid and diseased : it is partially anchy- 

 losed to the astragalus, which has participated in the disease. 



5262. The right tibia. 



This is in a sound state. The bone is two-fifths longer than in the Chimpanzee. The 

 articular surface upon the inner tuberosity is semi-oval instead of being semicircular as in the 

 Chimpanzee, and its longest diameter is from before backwards : this modification relates to 

 the corresponding modification of the inner condyle of the femur. The interarticular spine, 

 which is simple in the Chimpanzee, is here bifurcate. The border of the proximal tuberosi- 

 ties, formed by the original epiphysis, is thicker or deeper, especially round the inner side. 

 The surface for the fibula is much smaller than in the Chimpanzee, and the proximal end of 

 the tibia is less produced at that part backwards. The shaft is straighter, and is trihedral, 

 the posterior surface being more expanded and better defined by ridges from the surfaces 

 which converge to the anterior ridge. There is no rough depression on the inner side of the 

 proximal part of the ridge corresponding with that which is so strongly marked in the Chim- 

 panzee. The astragalar surface is triangular rather than subquadrate, owing to its greater 

 antero-posterior expansion at the outer part ; this difference is less marked in the variety 

 under comparison, in which, also, the shaft is more compressed from side to side, especially 

 at its proximal half, than in the White races. 



5263. The right fibula. 



5264. The left fibula. 



A greater part of the shaft is swollen, and exhibits other marks of inflammation and disease. 

 As compared with the same bone in the Chimpanzee, the fibula, besides the greater relative 

 length and slenderness of the shaft, has a proportionally smaller head, the articular facet on 

 which is more oblique, and the prominence anterior to it less produced : the prominence be- 

 neath it next the tibia is, however, broader than in the Chimpanzee. The form of the shaft 

 is more three-sided ; a transverse section of that of the Chimpanzee would be semi-oval. The 

 distal enlargement is relatively less, and its articular surface smaller. 



5265. The right astragalus. 



Besides its superior size, this differs from the astragalus in the Chimpanzee, in the greater 

 relative breadth of the tibial trochlear surface ; in the less extent of its outer or fibular sur- 

 face, the lower angle of which is much less produced outwards ; and in the absence of the 

 depression on the surface for the inner malleolus. The upper surface is slightly prolonged 

 upon the posterior prominence, which is longer but less deeply grooved than in the Chim- 

 panzee. The tubercular boundaries of the groove, especially the outer one, are less produced. 

 The outer concavity for the calcaneum is broader than in the Chimpanzee ; the anterior cal- 



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