Man-like, or in scientific parlance, Anthropoid Apes, are distinguished from others of the monkey tribe on account of their greater size and their greater resemblance to the human species. Within the last quarter of a century, they have, owing to the growing prominence of the doctrine of evolution, been raised to a much higher place than before as subjects of study for the naturalist, the scientist, the philosopher. From being little other than mere curiosities in animal life, they have become important objects of psychological inquiry, and have taken their place as factors not to be overlooked in the elevated regions of speculative thought. This is due almost solely to the change that has passed over our methods of studying animal life. We have ceased to regard the lower creatures as little better than pieces of living mechanism, and have come to view them as vital steps in the great ladder of progression which connects the higher with the lower orders of organic existence. Hence it is not now a matter of wonder that a whole volume of the ‘International Scientific Series’ should be devoted to the study of Man-like Apes. The volume, _Anthropoid Apes_ (London: Kegan Paul & Co.), is from the pen of Professor Hartmann of Berlin, and forms the fifty-third of the above valuable series of works. On account, says the author, of their external bodily characteristics, of their anatomical structure, and their highly developed intelligence, Anthropoids not only stand first among apes, but they take a still higher place, approximating to the human species. Their fossil remains carry us into a far-back period of prehistoric time; and even within historic times, we have them mentioned as early as 500 B.C. They were then known to the Carthaginians, who call them ‘_gorillai_,’ and describe them as hairy silvan creatures who replied to the attacks of the seafarers by throwing stones at them. The gorilla, the chimpanzee, the orang-utan, and the gibbon, are the chief of the animals included under the title Anthropoid Apes. They differ from each other and among themselves in external form according to the age and sex, the difference between the sexes being most strongly marked in the gorilla, and least apparent in the gibbon. ‘When a young male gorilla is compared with an aged animal of the same species, we are almost tempted to believe that we have to do with two entirely different creatures.’ Into the distinguishing physiological peculiarities of the external form of these creatures, we cannot of course enter here, and must refer to the full and elaborate investigations placed on record by Professor Hartmann.