COI^TRIBUTIONS TO THE THEORY OE EVOLUTION. 
203 
Now we see that, if the gorilla be put on one side, there is no approach to 
accordance between the calculated and observed statures''^ in the case either of the 
chimpanze or orang for any of the ten formulse. We conclude therefore, that if 
man and the chimpanze and orang have been derived from a common stock, they 
must have been directly selected with regard to stature and with regard to the 
lengths of the four chief long bones. In the case of the gorilla we notice, however, 
a remarkable accordance between the observed stature, and that calculated from the 
male reconstruction formulse in the case of man, when we use only formulae involving 
the femur and tibia. It would thus appear that if man and the gorilla have been 
differentiated from a common stock, they have been directly selected in the same 
manuer so far as femur and tibia are concerned, but in different directions when we 
consider humerus and radius—we are here referring only to the lengths of these 
bones. Re-examining the results for the male formulse from the standpoint of 
con'espondence in the femur and tibia between the gorilla and man, we see that the 
chimpanze comes nearer to man than the orang; the lengths of the femur and tibia 
have been modified in the former, but not to such a marked degree as in the case of 
the latter. Turning to the female reconstruction formulse we notice in (a) to (k) for 
the chimpanze and orang an accordance between the observed and calculated statures 
which is some 3 centims. to 6 centims. better, although still very poor. The reason 
for this is obvious, the stature of the woman for the same length of long bone is 
3 centims. to 6 centims. shorter than that of man, and accordingly the female formulm 
must give slightly better results than the male formulse when applied to the anthropo¬ 
morphous apes, which have for the same length of bone a markedly shorter stature 
than man. In the gorilla we have over-corrected the stature so far as femur and 
tibia are concerned by using the female formulse. One point, however, is of very 
great interest: while the female formulse for humerus, radius, or for humerus and 
radius give very bad results, even worse for the gorilla than they do for the 
chimpanze, yet the female formula for femur and humerus gives a sensibly better, 
and that for all the long bones a markedly better result for the stature than the 
corresponding male formulse. The difference here is not the 3 centims. to 6 centims. due 
to sex. The improvement in the result when we apply the female formulse for all four 
long bones to the estimate of the stature of the gorilla is noticeable also, if to a 
lesser degree, in the cases of the chimpanze and orang. We may sum up our 
results as follows :— 
(a.) Man is apparently differentiated from the chimpanze and orang by direct 
selection of stature, but this direct selection appears to be small in the case of the 
gorilla. 
* If tlie chimpanze and orang be treated as “ dwarf men,” and their statures estimated in the manner 
indicated on p. 224 below, the femur and tibia give statures, F, 115'5,105'0 ; T, 118'0, 112’5 respectively, 
nearer the actual values, in fact too small, but the radius and humerus still give values far too great. 
The stature of the gorilla as estimated from femur and tibia in this manner now becomes far too small. 
2 D 2 
