[3] See notes, p. [102], [106].
[6] Perfect, in the sense of highest stage of evolution, may seem a petitio principii. Leaving aside the consideration that no living creature is absolutely perfect, in the sense that its organization cannot become more efficient or proficient, we have here to deal with relative perfection of the whole organization. A fish or a snake is in its way more specialized than a mammal; but specialization does not necessarily mean height of development: it generally means life in a comparatively narrow groove. The acts of giving birth and nourishing the young with the mother's milk is a much higher stage than the act of laying eggs and letting them run their chance. The development of a hairy coat goes along with heightened temperature of the blood, subsequent greater independence of the surrounding temperature, and increased steady activity of the brain and other nerve-centres. The brain of the Mammalia, in its minute structure, is much more complex. This rule applies to some of the principal sense organs, chiefly the nose and the ear. The skeleton, not so much as a whole as in the various bones and joints, is more neatly finished, and built up more in conformity with 'scientific principles,' than is the case even with birds, in spite of their marvellous specialization. The same is the case with the vascular system, notably the heart and the veins, and with the excretory organs. In all of these many imperfections, still to be found in the other classes, have been corrected in Mammalia. The Primates take an easy first by their hands, and among them the apes and man himself by their brains.
[7] 'Die menschenähnlichen Affen und ihre Organisation im Vergleich zur menschlichen.' 1883.
[8] G. Schwalbe, 'In wiefern ist die menschliche Ohrmuschel ein rudimentäres Organ?'—In what Respects is the Human Outer Ear a Rudimentary Organ? (Archiv f. Anatomie und Physiologie, 1889).
[9] Wiedersheim, 'Der Bau des Menschen als Zeugniss für seine Vergangenheit.' Freiburg, 1888. Translated: 'The Structure of Man an Index to his Past History.' London, 1895.
[10] Pithecanthropus erectus. 'Eine menschenähnliche Uebergangsform aus Java' ('A Human-like Transitional Form'). Batavia, 1894.
[11] On the day after the delivery of this address Dr. Dubois exhibited the cranium of Pithecanthropus, from which he had removed the stony matrix which filled the inside, in order to examine the impression left by the cerebral convolutions. He was able to show that they also are very human, and more highly developed than those of the recent apes.
[12] L. Manouvier: 'Deuxième étude sur le Pithecanthropus erectus comme précurseur présumé de l'homme.' (Bulletins de la Soc. d'Anthropologie de Paris, 1895.)