A Transitional Form between Man and the Apes. 9 
declared the femur to be human-like in its form. It is human-like in all its 
essential features. Had I found the femur alone, I think I should have been 
misled to declare it to be the femur of a Man—by far the oldest Man—almost 
certainly the first Tertiary Man. I believe I should have remarked then also the 
less important features in which, even making a very large allowance for the 
variability which this bone shows in Man, it differs from a human femur. But 
these slight differences I should perhaps have regarded as evidence of another 
species only. But now, considering its, in my opinion, unmistakable connection 
with the very ape-like cranium and these simian teeth, without forgetting that the 
femur is human-like in all its essential features, I cannot regard it as the femur of 
a Man. And considering the finding of it in close proximity to the ape-like skull 
and teeth, I see in the features by which this femur is different from all existing 
races of Man—though they may be mechanically unimportant—more than a special 
ditference. 
I have to account, then, for the heterogeneous combination of these parts in 
one body which, according to our knowledge of living species, seems to be 
paradoxical. 
Professor Manouvrier, the well-known Paris anthropologist, to whom I showed 
the Javanese femur, declared he had never seen, as far as he could remember, 
a similar feature of the popliteal space in human thigh-bones, of which he has 
examined many hundreds.* I acknowledge that the possibility still exists that 
the bone, nevertheless, may be a human femur. But considering the circum- 
stances under which the femur was found, namely, in exactly the same horizon 
of one stratum and in the closest proximity to the skull-cap and the teeth, 
which circumstance prove their exact synchronism, it seems to me to be far more 
natural to doubt the human nature of the femur in case the other remains 
should be proved, on account of the anatomical examination, to be not human, 
Manouvrier and Dr. Arthur Keitht point out that the human form of the Trinil 
femur is not sufficient to prove that it did not belong to the same individual as 
the skull-cap; for, the phylogenetic evolution of the human femur ought to 
have preceded that of the skull, as the erect attitude and the erect locomotion 
have been the cause of the intellectual perfection. Suppose a species of Anthro- 
poid Ape—whose frame rather resembles the human—suppose a large Hylo- 
bates, should strive to perfect the pedal locomotion, which this genus 
already has when walking on the ground—it would, on account of the close 
relation existing between form and function of the femur, be hardly imaginable 
* Later on he wrote to me, that he at last had found some specimens showing similar, though not 
exactly the same, features. These cases may be regarded as atavistic varieties. 
} L. Manouvrier, 7. ¢.; A. Keith, J. ¢. 
TRANS, ROY, DUB. SOC., N.S. VOL, VI., PART I, C 
