I will now adduce the two hypotheses above alluded to as conceivable suggestions touching the mode of transition. First, let us try to imagine an anthropoid ape, social in habits, using its voice somewhat extensively as an organ of sign-making after the manner of all other species of social quadrumana, and possibly somewhat more sagacious than the orang-outang mentioned in my previous work,[309] or the remarkable chimpanzee now in the Zoological Gardens, which, in respect of intelligence as well as comparative hairlessness and carnivorous propensities, appears to be the most human-like of animals hitherto discovered in the living state.[310] It does not seem to me difficult further to imagine that such an animal should extend the vocal signs which it habitually employs in the expression of its emotions and the logic of its recepts, to an association with gesture-signs, so as to constitute sentence-words indicative of such simple and often-repeated ideas as the presence of danger, discovery of food, &c. Nay, I do not think it is too much to suppose that such an animal may even have gone so far as to make sounds which were denotative of a few of the most familiar objects, such as food, child, enemy, &c., and also, possibly, of frequently repeated forms of activity; for this, as I have shown at considerable length, is no more than we actually observe to be done by animals which are lower in the scale of intelligence; and although it is not done by articulate signs (except in the psychologically poor instance of talking birds), this, as I have also shown, is a matter of no psychological import. Whether the denotative stage of language in the ape was first reached by articulation, or (as I think is very much more probable) by vocal sounds of other kinds assisted by gestures and grimace, is similarly immaterial. In either case the advance of intelligence which would thus have been secured would in time have reacted upon the sign-making faculty, and so have led to the extension of the vocabulary, both as to sounds and gestures. Sooner or later the vocal signs—assisted out by gestures and ever leading to a gradual advance of intelligence—would have become more or less conventional, and so, in the presence of suitable anatomical and social conditions, articulate. Thus far I cannot see anything to stumble over, when we remember all that has been said upon the conventional signs which are used by the more intelligent of our domesticated animals, and even by talking birds.[311]