Of the capacity of the calvarium, Dubois says: “I found the above-mentioned cavity measured 550 c.cm. The cast of the cavity of the Neanderthal skull taken to the same plane measures 750 c.cm.” (_Loc. cit._, p. 450, footnote.) His first estimate of the total cranial capacity of _Pithecanthropus_ was 1000 c.cm., but, later on, when he decided to reconstruct the skull on the basis of the cranium of a gibbon (_Hylobates agilis_) rather than that of a chimpanzee (_Troglodytes niger_), he reduced his estimate of the cranial capacity to 900 c.cm. Recently, it is rumored, he has increased the latter estimate, as a sequel to his having removed by means of a dentist’s tool all the siliceous matter adhering to the skull-cap. As regards shape, the calvarium seems to resemble most closely the cranial vault of gibbon. This similarity, as we have seen, led Dubois to reconstruct the skull on hylobatic lines—“the skull of Hylobates agilis,” says Dubois, “ ... strikingly resembles that of Pithecanthropus.” (_Loc. cit._, p. 450, footnote.) The craniologist Macnamara, it is true, claims that the skull-cap most closely approximates the Troglodyte type. Speaking of the calvarium of Pithecanthropus, the latter says: “The cranium of an average adult male chimpanzee and the Java cranium are so closely related that I believe them to belong to the same family of animals—_i.e._ to the true apes.” (_Archiv. für Anthropologie_, XXVIII, 1903, pp. 349-360.) The large cranial capacity, however, would seem to favor Dubois’ interpretation, seeing that gibbons have, in proportion to their bodies, twice as large a brain as the huge Troglodyte apes, namely, the chimpanzee and the gorilla. The maximum cranial capacity for any ape is from 500 to 600 c.cm. Hence, with 900 c.cm. of cranial capacity estimated by Dubois, the Pithecanthropus stands midway between the ape and the Neanderthal Man, a human dwarf, whose cranial capacity Huxley estimated at 1,236 c.cm. This consideration, however, does not of itself entitle the Pithecanthropus to be regarded as a connecting link between man and the anthropoid apes. In all such comparisons, it is the _relative_, and not the _absolute_, size of the brain, which is important. The elephant for example, has as large a brain as a man, but the elephant’s brain is small, in comparison to its huge body. The brain of a mouse is insignificant, as regards absolute size, but, considered in relation to the size of the mouse’s body, it is as large as, if not larger than, that of an elephant, and hence the elephant, for all the absolute magnitude of its brain, is no more “intelligent” than a mouse. As we have already seen, man’s brain is unique, not for its absolute size, but for its weight and enormous cortical surface, considered with reference to the comparatively small organism controlled by the brain in question. It is this excess in size which manifests the specialization of the human brain for psychic functions. The Weddas,