"These rejoinders are correct, for when _locomotion_ is the matter in question, it is evident that due consideration must be paid to the muscles, which are the active agents in that function at least as much as the bones, which only serve as points of attachment and are only passive. "3rd. In some of the races of man, the arch of the skull, instead of presenting a uniform curve in the transverse direction, bends a little towards the top of the two sides, and rises towards the median line (New Caledonians, Australians, &c.). It is asked if this is not a preliminary step towards the bony crests which rise in this region in some of the anthropomorphous apes? "Again we reply in the negative; for, in the latter, the bony crests arise from the walls of the skull, and do not form any part of the arch. "4th. Is it not very remarkable that we find the orang to be brachycephalous, just like the Malay, whose country it inhabits, and that the gorilla and chimpanzee are dolichocephalous like the negro? Is not this fact a reason for our regarding the former animal as the ancestor of the Malays, and the latter of the African nations? "Even if the facts brought forward were correct, the inference which is drawn from them would be far from satisfactory. But the coincidence which is appealed to does not exist. In point of fact, the orang, which is essentially a native of Borneo, lives among the Dyaks and not among the Malays; now the Dyaks are rather dolichocephalous than brachycephalous. With respect to gorillas being dolichocephalous, they cannot at least be so generally; as out of _three_ female specimens of this ape which were examined, two were brachycephalous (Pruner-Bey). "5th. The brains of microcephalous individuals present a mixture of human and simial characteristics, and point to some intermediate conformation, which was normal at some anterior epoch, but at the present time is only realised by an arrest of development and a fact of atavism. "Gratiolet's investigations of the brain of the ape, normal man and small-brained individuals, have shown that the similarities pointed out are purely fallacious. People have thought that they could detect them, simply because they have not examined closely enough. In the last named, the human brain is simplified; but this causes no alteration in the _initial plan_, and this plan is not that which is ascertained to exist in the ape. Thus Gratiolet has expressed an opinion which no one has attempted to controvert: 'The human brain differs the more from that of the ape the less the former is developed, and an arrest of development could only exaggerate this natural difference.... The brains of microcephalous individuals, although often less voluminous and less convoluted than those of the anthropomorphous apes, do not on this account become like the latter.... The idiot, however low he may be reduced, is not a beast; he is nothing but a deteriorated man.'