ABSTRACT
The significance of functional differentiation in the Primates can be evaluated against the background of paleontological fact and speculation. The higher Primates are believed, on slight paleontological evidence, to have been derived from the tarsioid group. In the light of the paleontological data bearing on the question of the sub-division of the Catarrhini, it is plain that the platyrrhine stem must have diverged during some phase of the Eocene. Paleontology is altogether unable to provide the answer to the question of man’s precise relationship with the apes. The increase in the intensity of the precipitin response observed in passing from the Hapalidæ to Man along the lines of accepted classification, however, is suggestive of an evolutionary gradation of affinity in the sub-order Pithecoidea. Lemuroidea should be combined with the Menotyphla and given ordinal rank distinct from monkeys, apes, and man.
