The epoch during which these sentence-words prevailed was probably immense; and, as we have before seen, far from having been inimical to gesticulation, must have greatly encouraged it—raising, in fact, the indicative phase of language to the level of elaborate pantomime. Out of the complex of sentence-words and gesture-signs thus inaugurated, grammatical forms became slowly evolved, as we know from the independent witness of philology. But long before grammatical forms of any sort began to be evolved, a kind of uncertain differentiation must have taken place in this protoplasmic material of speech, in such wise that some sentence-words would have tended to become specially denotative of particular objects, others of particular actions, states, qualities, and relations. This “primitive streak,” as it were, of what was afterwards to constitute the vertebral column of articulated language in the independent yet mutually related “parts of speech,” must in large measure have owed its development to gesture. Now, by this time, gesture itself must already have acquired an elementary kind of syntax, such as belongs even to semiotic movements of an infant who happens to be late in beginning to speak.[332] This elementary kind of syntax would necessarily be taken over by, or impressed upon, the growing structure of speech, at all events so far as the principles and the order of apposition were concerned. Moreover, this sign-making value of apposition would at the same time have been promoted within the sphere of articulate signs themselves. For, as we have previously seen, as soon as words become in any measure denotative, they immediately begin to undergo a connotative extension;[333] and with this progressive widening of signification, words require to be more and more frequently used in apposition. Quite independently of any as yet non-existing powers of introspective thought, the external “logic of events” must have constantly determined such apposition of receptually connotative terms, as we have already so fully seen in the case of the growing child. Thus the conditions were laid for the tripartite division—the genitive case, the adjective, and the verb. Not till long subsequent ages, however, would this division have taken place in its fulness. During the time which we are now contemplating, there could have been no distinction at all between the genitive case and the adjective; neither could there have been any verbs as independent parts of speech. Nevertheless, already some of the denotative signs would have been used as names of particular objects, others of particular qualities, and yet others of particular actions, states, and relations. Not yet deserving to be regarded as fully differentiated parts of speech, these object-words, quality-words, &c., would have resembled those with which we are all well acquainted in nursery language, and which still survive, in a remarkably large measure, among many dialects of a low order of development.