. 
MAN’S FAMILY TREE. 551 
Almost from the base of this central anthropoid stem issues the line which led to the 
gibbon, diverging and ascending to a position far to the right of the African anthro- 
poids. From the same central anthropoid stem, but a little higher up, emerges the 
human stem; it diverges and ascends to the left, so that ultimately man takes up a 
position as far to the left of the gorilla and chimpanzee as the gibbon holds on their 
right. Dr. Schultz regards the gibbon and man as contrasted forms, possessing 
evolutionary pedigrees of nearly equal antiquity. The gibbons represent an arm- 
using or brachiating orthograde primate ; man represents a leg-using or cruriating 
orthograde primate. Big-brained man has undergone many and great structural 
changes, while the small-brained gibbon has been relatively conservative and undergone 
specialisation of a minor kind. There is much to be said in support of Dr. Schultz’s 
conception. 
There are many other recent schemes showing man’s origin and relationship which 
I should have liked to have discussed with you had time permitted. There is, in 
particular, an instructive pedigree outlined by Dr. C. Tate Regan,? but I must limit 
myself to a brief discussion of the family tree* which Dr. Henry Fairfield Osborn 
has drawn up to represent his conception of man’s origin. .Dr. Osborn’s tree differs 
from those I have so far shown to you in one important respect. Its trunk, which 
is rooted deep in the oligocene, divides almost at once into right and left stems, the 
right stem breaking up, as it ascends, to give birth to the known forms of anthropoid 
ape, both extinct and living. The other main stem ascends to the left and, as it 
rises towards and enters the pleistocene, branches into the known forms of man, living 
and extinct. Dr. Osborn thus excludes an anthropoidal stage from human ancestry. 
He supposes that man and ape diverged from a common ancestry in the earlier half 
of the oligocene period. Dr. Osborn’s opinion will carry weight with every serious 
student; he has had a richer experience than anyone in tracing the evolutionary 
histories of the higher mammals, The likenesses which man bears to the great 
anthropoids, in brain and in body, he holds, are to be regarded as independent 
acquisitions; he has noted similar instances of ‘ parallelism’ in many lines of 
mammalian evolution. He has examined anthropoids living and extinct, and nowhere 
finds a form sufficiently generalised to serve as a starting-point for human evolution, 
until he passes back to the early eocene primates of the type represented by 
Propliopithecus. 
There is no need for me to criticise Dr. Osborn’s theory of man’s evolution ; that 
has already been done by Dr. W. K. Gregory. I would merely say this, that the 
Osborn scheme is framed not to explain the wealth of facts already at our disposal, 
but to account for certain ideals which his imagination has fashioned out of a wide 
and ripe experience. For my part I can see no way of accounting for man’s structure, 
his posture and manner of progression, except by supposing that in his evolution 
he has passed through a small anthropoid stage and then a large anthropoid stage. 
These stages we know of ; we have no evidence of such stages as must be postulated 
in Dr. Osborn’s theory. 
Thus I end by giving my support to that form of Man’s Family Tree which was 
drafted by Haeckel sixty-five years ago. Knowledge has greatly increased since 
then; but even when this new knowledge is incorporated as has been done by 
Gregory, Schultz and many others, the scheme is essentially that which Haeckel 
drafted under the inspiration of Darwin and of Huxley. We are all agreed that 
anthropoid and man have a common ancestry ; it is merely the degree of relaticnship 
which is in dispute. 
2 The Evolution of the Primates. Annals & Mag. Nat. Hist., 1930, September 10, 
vol. vi., p. 383. 
8 Published in Long Island Medical Journal. October 1927; also in Paleobio- 
logica, 1928, vol. i., p. 193. 
