The recognition of individuals next made its appearance in the reptiles of the Carboniferous and Permian epochs; while the birds of the Oölitic and Cretaceous periods were the first to dream, and are thus placed on an intellectual level with a child of five or six months. The emotional development coincides with the intellectual, just as in the case of the infant, for we find fear manifesting itself among the lower molluscs, pugnacity among the crustaceans, play among spiders and crabs, anger among reptiles, and emulation, jealousy, joy, and grief among birds. We now rise in the palæontological scale to the Tertiary period, and find in the Eocene age equine and other mammal forms, such as cats and pigs, which are capable of understanding words and signs, and among which we notice a manifestation of sympathy, curiosity, revenge, and gratitude. In the early Meiocene age we have monkeys, dogs, and elephants exhibiting the clearest signs of true reason, as may be observed at the present day, and at the same time manifesting such emotional signs as pride, shame, deceitfulness, passionateness, cruelty, and ludicrousness, which places them on an intellectual par with the infant of less than a year old. In the later Meiocene age we have anthropoid apes, which may be placed on a level with one-year-old infants, and from which evolved apes of a higher order, which acquired the faculty of articulation, and, afterwards becoming more human, the knowledge of the use of simple instruments, thus reaching the intellectual level of the child of fifteen months old. As the apes became more and more human in the later Meiocene and early Pleistocene ages, they gradually acquired the faculty of acting in concert and of speech; and when, having arrived at that stage of development in which they partook more of the character of savage man than human ape, judgment, recollection, self-consciousness, and, lastly, definite morality manifested themselves, thus raising the ape-like man to the level of the child of two and a half years. In the lowest savages of to-day, as well as in the old descendants of the ape-like men, superstition developed to a large extent at the same time that the emotional unfolding proceeded in the direction of avarice, envy, hate, hope, vanity, mirth, a love of the beautiful, and afterwards art appreciation, awe, reverence, remorse, courtesy, melancholy, and ecstasy, precisely as with the child of from five to ten years of age. As the race improved, becoming in turn semi-savage, semi-civilised, civilised, and cultured, the intellectual powers, of course, developed similarly, until, at the present day, we find men possessed of the most wonderful mental grandeur, we might almost say, conceivable. But this would be saying too much, for we must not forget that, just as evolution has continued in the past from eternity, so will it continue in the future to eternity; and who can tell to what heights the human mind may soar in the future?