The Catarhine monkeys include the Macaques, most of which are Asiatic, a few are African and one European; the Cercopitheques, most of which are African and a few Asiatic; and other genera which characterize one or other continent exclusively. Thus the true baboons (Papio) are African, as are the thumbless monkeys (Colobus) and the chimpanzees (Troglodytes). The Semnopithecus, gibbons, and orangs are peculiarly Asiatic. Palæontology has shown that a macaque, a gibbon, and an orang existed during the older Tertiary times in Europe, and that Semnopithecus existed in Miocene times in India. But all the fossil remains of Quadrumana in the Old World belong to the family Catarhina, which is still exclusively confined to that great division of dry land. The tailless macaque (Innus silvanus) of Gibraltar may have existed in that part of the Old World before Europe was separated by the Straits of Gibraltar from Africa. Fossil remains of Quadrumana have been discovered in South America; they indicate Platyrhine forms: a species, for example, allied to the howlers (Mycetes), but larger than any now known to exist, has left its remains in Brazil. While adverting to the geographical distribution of Quadrumana, I would contrast the peculiarly limited range of the orangs and chimpanzees with the cosmopolitan powers of mankind. The two species of orang (Pithecus) are confined to Borneo and Sumatra; the two species of chimpanzee (Troglodytes) are limited to an intertropical tract of the western part of Africa. They appear to be inexorably bound by climatal influences regulating the assemblage of certain trees and the production of certain fruits. With all our care, in regard to choice of food, clothing, and contrivances for artificially maintaining the chief physical conditions of their existence, the healthiest specimens of orang or chimpanzee, brought over in the vigor of youth, perish within a period never exceeding three years, and usually much shorter in England. By what metamorphoses, may we ask, has the alleged humanized chimpanzee or orang been brought to endure all climates? The advocates of transmutation have failed to explain them. Certain it is that those physical differences in cerebral, dental, and osteological structure which place, in my estimate of them, the genus Homo in a distinct group of the mammalian class, zoologically of higher value than the order, are associated with equally contrasted powers of endurance of different climates, whereby man has become a denizen of every part of the globe from the Torrid to the Arctic zones. Climate rigidly limits the range of the Quadrumana latitudinally; creational and geographical causes limit their range in longitude. Distinct genera represent each other in the same latitudes of the New and Old Worlds; and also, in a great degree, in Africa and Asia. But the development of an orang out of a chimpanzee, or reciprocally, is physiologically inconceivable.