Talking birds—which happen to be the only animals whose vocal organs admit of uttering articulate sounds—show themselves capable of correctly using proper names, noun-substantives, adjectives, verbs, and appropriate phrases, although they do so by association alone, or without appreciation of grammatical structure. Words are to them vocal gestures, as immediately expressive of the logic of recepts as any other signs would be. Nevertheless, it is important to observe that this faculty of vocal gesticulation is the first phase of articulate speech in a growing child, is the last to disappear in the descending scale of idiocy, and is exhibited by talking birds in so considerable a degree that the animals even invent names (whether by making distinctive sounds, as a particular squeak for “nuts,” or by applying words to designate objects, as “half-past-two” for the name of the coachman)—such invention often clearly having an onomatopoetic origin, though likewise often wholly arbitrary. * * * * * I will now conclude this chapter by detailing evidence to show the extent to which, under favourable circumstances, young children will thus likewise invent arbitrary signs, which, however, for reasons already mentioned, are here almost invariably of an articulate kind. It would be easy to draw this evidence from sundry writers on the psychogenesis of children; but it will be sufficient to give a few quotations from an able writer who has already taken the trouble to collect the more remarkable instances which have been recorded of the fact in question. The writer to whom I allude is Mr. Horatio Hale, and the paper from which I quote is published in the _Proceedings of the American Association for the Advancement of Science_, vol. xxxv., 1886. “In the year 1860 two children, twin boys, were born in a respectable family residing in a suburb of Boston. They were in part of German descent, their mother’s father having come from Germany to America at the age of seventeen; but the German language, we are told, was never spoken in the household. The children were so closely alike that their grandmother, who often came to see them, could only distinguish them by some coloured string or ribbon tied around the arm. As often happens in such cases, an intense affection existed between them, and they were constantly together. The remainder of their interesting story will be best told in the words of the writer, to whose enlightened zeal for science we are indebted for our knowledge of the facts.