50 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 83 



ostosis below the trochanter minor takes the place of the intermuscular 



connective tissue between the vastus medialis and the adductors 



The resemblance of the fossil femur to that of J\Ian, in contrast to 

 the Apes, is very marked in the knee-joint, which was adapted for 



perfect extension of the leg In the rontgenogram, both in that 



of the upper end of the femur and the lower end, the " trajectoria " of 

 the human type may be recognized, though on account of the filled 

 cavities they are not so clear as in other thigh-bones. 



" Two characters distinguish the Trinil femur very decidedly from 

 that of Man. These are in physiological relation to each other, though 

 the first refers to the form of the lower part of the diaphysis and 

 the other to that of the trochanter major at the superior extremity 

 of the femur. Down to low on the popliteal surface and beginning 

 at more than 11 cm. above the level of the patellar articular surface 

 the back side shows a median swelling and rounding." In no human 

 femur described or known to the author does this convexity rise in 

 the same degree or does it bulge upwards to such a buttress-like 

 median swelling as in the Pithecanthropus. 



In the " cross-sections of the fossil femur the complete absence of 

 an angulus medialis also strikes the eye, in contrast with the human 

 femur, but in accordance with this bone in Apes. In Man the inner 

 side (as angulus medialis) remains free from attachment of muscles ; 

 in the Apes, on the other hand, the origin of the vastus intermedins 

 or of the vastus medialis continues on the inner side of the femur, 

 enveloping this bone continuously. Tims it seems also to have been 

 in Pithecanthropus." 



The peculiar shape of the lowest third of the femur is attributable, 

 according to Dr. Dubois, to static and mechanical catises and hence 

 modified mu.scle attachments, in the lower limb of the Pithecan- 

 thropus. 



The second special character " that very definitely distinguishes 

 the femur of Pithecanthropus from that of Man, and which is in 

 physiological relation to the just described character, is the position 



of the trochanter major in the continuation of the diaphysis 



The posterior border with the whole great trochanter is directed 

 vertically upward. In Man, on the other hand, as well as in almost 

 all Apes, Monkeys and Baboons the posterior border with the whole 

 great trochanter has an ol)lique direction upwards and forward (fig. 

 32, femur of a Dutchman). In Pithecanthropus the great trochanter 

 is not placed on the diaphysis slanting forward as in Man and in 

 the whole Monkey tribe, with the exception of two genera, but forms 



