Vice-President's Address. 19 



bounded is either concave or flat, but occasionally it pre- 

 sents a varying degree of convexity. In the Trinil femur 

 this convexity was so pronounced as to give the shaft almost 

 a cylindrical outline. Such a condition is certainly very 

 rare among human femora, although it does undoubtedly 

 occur among those of lower races, and is to be regarded as 

 an anthropoid rather than a human character. 



In connection with the condyles of the femur and the 

 knee-joint, into the formation of which they enter, there are 

 again distinct evidences of their evolution, for they still sub- 

 serve the functions of support and locomotion, although in 

 association with a changed attitude. 



Originally the knee-joint presented three joint cavities, 

 viz., a femoro-patellar and two femoro-tibial. In man's 

 knee-joint, the ligamentum mucosum and the ligamenta 

 alaria of the synovial membrane, with the crucial liga- 

 ments, provide the remains of the structures which effected 

 this subdivision. But even the condyles of the femur retain 

 traces of this subdivision of the joint, viz., in man the lateral 

 borders of the two condylar articular surfaces always present 

 slight indentations or notches, which indicate the original 

 limitations between them and the patellar surface of the 

 condyles. Upon some bones these indentations become 

 quite distinct notches, and practically all femora (notwith- 

 standing the continuity between the patellar and tibial por- 

 tions of the articular surface) present a faint ridge upon the 

 articular cartilage, in place of the original non-articular area 

 of separation. It need scarcely be said that among apes 

 these indications of primitive conditions are much more 

 definite than in man. 



A further evidence of evolution is to be seen in the exten- 

 sion of the condylar articular surfaces upon the adjacent 

 popliteal surface. This is a character of the femur in certain 

 squatting races, and has generally been attributed to the 

 hereditary transmission of an acquired character ; but 

 Dr Waterston has shown that this femoral character is a 

 constant feature among all foetal European femora, and it 

 must therefore be regarded as a character which occasionally 

 persists in the adult stage rather than one which is acquired. 



