424 Proceedings of Royal Society of Edinburgh. [sess. 
race, yet that they still appeared to be human, and that between 
them and an undoubted anthropoid ape there was an abyss ; 
though the interval was not quite so great as that between the 
men of Spy and the fossil Dryopithecus of the Middle Miocene 
period. 
MM. Fraipont and Lohest attached considerable importance to 
the form and extent of the antero-posterior curvature of the condyles 
of the femur, and to modifications in the curvatures of the articular 
surfaces of the head of the tibia, so as to make them conform to 
the large articular surfaces of the femoral condyles. They con- 
sidered that with such an extent of curvature backwards of the 
femoral condyles, the erect human position would not have been 
possible, and that the trunk had been projected forwards. They 
are inclined to think that the attitude of these men, when standing, 
partook more of that of anthropoid apes, and was therefore more 
pithecoid than human. 
Dr Collignon had previously called attention,* in his description 
of the human skeletons found in 1869 at Bollwiller, in the Depart- 
ment of the Upper Rhine, to the backward slope (retroversion) of 
the head of the tibia, which gave the articular surface an oblique 
direction from above downwards, and from before backwards. He 
regarded it as a character akin to that found in the gorilla, associated 
with demi-flexion of the leg, and rendering the vertical attitude 
difficult, so that the body was less erect during progression than 
in existing men. 
In a review! of MM. Fraipont and Lohest’s memoir, Dr Collignon 
expressed the opinion that the characters of the head of the tibia 
in the Bollwiller skeletons, existed in a higher degree in the tibiae 
of the men of Spy. In the following year M. Fraipont published 
an account J of a fresh examination of the tibiae obtained at Spy, 
and corroborated Dr Collignon’s opinion. He stated that the in- 
curvation of the head upon the body of the tibia was very accentu- 
ated in these skeletons, and he considers that he is, as a result of 
this additional inquiry, still more justified in concluding that the 
men of Spy had an attitude less vertical than existing man, and 
* Revue d’ Anthropologie, 1880, vol. iii. pp. 406, 412. 
t Revue d' Anthropologie, 1887, 3rd series, vol. ii. p. 742. 
+ Ibid., March 1888, vol. iii. p. 145, 
