Concerning the accuracy of these observations I have no doubt, and I could corroborate most of them were it necessary. It appears, then, first, that talking birds may learn to associate certain words with certain objects and qualities, certain other words or phrases with the satisfaction of particular desires and the observation of particular actions; words so used we may term vocal-gestures. Second, that they may invent sounds of their own contriving, to be used in the same way; and that these sounds may be either imitative of the objects designated, as the sound of running fluid for “Water,” or arbitrary, as the “particular squeak” that designated “Nuts.” Third, but that in a much greater number of cases the sounds (verbal or otherwise) uttered by talking birds are imitative only, without the animals attaching to them any particular meaning. The third division, therefore, we may neglect as presenting no psychological import; but the first and second divisions require closer consideration. In designating as “vocal gestures”[86] the correct use (acquired by direct association) of proper names, noun-substantives, adjectives, verbs, and short phrases, I do not mean to disparage the faculty which is displayed. On the contrary, I think this faculty is precisely the same as that whereby children first learn to talk; for, like the parrot, the infant learns by direct association the meanings of certain words (or sounds) as denotative of certain objects, connotative of certain qualities, expressive of certain desires, actions, and so on. The only difference is that, in a few months after its first commencement in the child, this faculty develops into proportions far surpassing those which it presents in the bird, so that the vocabulary becomes much larger and more discriminative. But the important thing to attend to is that at first, and for several months after its commencement, the vocabulary of a child is always designative of particular objects, qualities, actions, or desires, and is acquired by direct association. The distinctive peculiarity of human speech, which elevates it above the region of animal gesticulation, is of later growth—the peculiarity, I mean, of using words, no longer as stereotyped in the framework of special and direct association, but as movable types to be arranged in any order that the meaning before the mind may dictate. When this stage is reached, we have the faculty of predication, or of the grammatical formation of sentences which are no longer of the nature of vocal gestures, designative of particular objects, qualities, actions, or states of mind: but vehicles for the conveyance of ever-changing thoughts.