[230] De Lamarck, "Philosophie Zoologique," vol. i. c. 7, and "Histoire Naturelle des Animaux sans Vertèbres," vol. i. Introd. pp. 180-212.
[232] Animated by the feeling of this truth, Robert Owen, after passing in review the numerous and often very large Australian fossile _marsupialia_--sometimes as big as the rhinoceros--came as early as 1842 to the conclusion, that a large beast of prey must have contemporaneously existed. This conclusion was afterwards confirmed, for in 1846 he received part of the fossile skull of a beast of prey of the size of the lion, which he named _thylacoleo_, _i.e._ lion with a pouch, since it is also a marsupial. (See the "Times" of the 19th of May, 1866, where there is an article on "Palæontology," with an account of Owen's lecture at the Government School of Mines.) [Add. to 3rd ed.]
[233] Kirby and Spence, "Introduction to Entomology," vol. i. p. 355. [Add. to 3rd ed.]
[234] Blumenbach, "De hum. gen. variet. nat." p. 50. Sömmering, "On the Negro," p. 8.
As the will has equipped itself with every organ and every weapon, offensive as well as defensive, so has it likewise provided itself in every animal shape with an _intellect_, as a means of preservation for the individual and the species. It was precisely in this account that the ancients called the intellect the ἡγεμονικόν, _i.e._ the guide and leader. Accordingly the intellect, being exclusively destined to serve the will, always exactly corresponds to it. Beasts of prey stood in greater need of intellect, and in fact have more intelligence, than herbivorous animals. The elephant certainly forms an exception, and so does even the horse to a certain extent; but the admirable intelligence of the elephant was necessary on account of the length of its life (200 years) and of the scantiness of its progeny, which obliged it to provide for a longer and surer preservation of the individual: and this moreover in countries teeming with the most rapacious, the strongest and the nimblest beasts of prey. The horse too has a longer life and a scantier progeny than the ruminants, and as it has neither horns, tusks, trunk, nor indeed any weapon save perhaps its hoofs, it needed greater intelligence and swiftness in order to elude pursuit. Monkeys needed their extraordinary intelligence, partly because of the length of their life, which even in the moderate-sized animal extends to fifty years; partly also because of their scanty progeny, which is limited to one at a time, but especially because of their _hands_, which, to be properly used, required the direction of an understanding. For monkeys depend upon their hands, not only for their defence by means of outer weapons such as sticks and stones, but also for their nourishment, this last necessitating a variety of artificial means and a social and artificial system of rapine in general, the passing from hand to hand of stolen fruit, the placing of sentinels, &c. &c. Add to this, that it is especially in their youth, before they have attained their full muscular development, that this intelligence is most prominent. In the _pongo_ or ourang-outang for instance, the brain plays a far more important part and the understanding is much greater during its youth than at its maturity, when the muscular powers having attained full development, they take the place of the proportionately declining intellect. This holds good of all sorts of monkeys, so that here therefore the intellect acts for a time vicariously for the yet undeveloped muscular strength. We find this process discussed at length in the "Résumé des Observations de Fr. Cuvier sur l'instinct et l'intelligence des animaux," par Flourens (1841), from which I have quoted the whole passage referring to this question in the second volume of my chief work, at the end of the thirty-first chapter, and this is my only reason for not repeating it here. On the whole, intelligence gradually increases from the rodents[235] to the ruminants, from the ruminants to the pachyderms, and from these again to the beasts of prey and finally to the _quadrumana_, and anatomy shows a gradual development of the brain in similar order which corresponds to this result of external observation. (According to Flourens and Fr. Cuvier.)[236] Among the reptiles, serpents are the most intelligent, for they may even be trained; this is so, because they are beasts of prey and propagate more slowly than the rest--especially the venomous ones. And here also, as with the physical weapons, we find the will everywhere as the _prius_; its equipment, the intellect, as the _posterius_.