hrdliCka] skeletal. REMAINS OF EARLY MAN 355 



verse diameter, while in the human femur it is of greater transverse 

 than antero-posterior dimension. 



''In the human femur the patellar surface is found separated from 

 the condylar surface by two transverse depressions, sufficiently 

 broad but of little depth; they are the 'transverse fossae,' which, 

 however, do not interrupt the continuation of the ridges wliich 

 laterally limit the patellar trochlea. . . . These transverse depres- 

 sions I have not observed in any of the mammals that I have had the 

 opportunity to examine, not even among the primates, with the 

 exception of the anthropomorphs, and it is indubitable that they 

 are related with the biped and more or less erect position. . . . These 

 depressions not only separate in the Tetraprothomo the patellar field 

 from the condylar planes, but they also interrupt the ridges which 

 limit laterahy the patellar surface . . . further proof that the 

 Tetraprothomo was a biped. . . . 



"There are, however, between man and the Tetraprothomo some 

 notable differences. In the femur of the latter the planes of the 

 condyles are quite convex and they narrow notably backward, while 

 in man they are nearly flat and in breadth nearly equal in front and 

 behind, wliich gives to the inferior surface of the bone apparently 

 a very distinct aspect. 



"It is clear that the greater flattening of the inferior plane of the 

 condyles and its posterior broadening in the femur of man are the 

 result of the erect position; it is, however, also evident that man did 

 Bot accpiire these characteristics suddenly but very gradually, as a 

 result of a cause wliich acted in the same direction during a long space 

 of time, and it is natural to suppose that tliis flattening and broadening 

 of the condylar surfaces continue still in augmentation at the actual 

 time. In Tetraprothomo it can be said these characteristics are in the 

 beginning of their formation. . . . The femur of Spy and that of 

 Ovejero occupy an intermediary position between the actual man and 

 that of the Tetraprothomo in these respects, but are still nearer the 

 latter. 



"The patellar troclilea is the part in which perhaps the femur of the 

 Tetraprothomo is more distant from the same bone in man. It differs 

 in the fact that it is farther extended from above downward, that it 

 is more arched in the same direction, and is of a more symmetric 

 form. The lateral ridges wliich limit the trochlea are more promi- 

 nent and acute, characteristics which distinguish them from the 

 same crests in the femur of man. , . . With tliis, the patellar trochlea 

 of the femur of the Tetraprothomo extends farther from above down- 

 ward than transversely, that is, it is of greater height than breadth, 

 inversely to what succeeds in man, in whom it is notably more broad 

 than high, while at the same time the external crest is stronger and 

 more prominent than the internal and the superior border of the 



