run a parallel course of development_, this phase passes into the other—the mere fact that this is so cannot be quoted as evidence that a similar transition never took place in the psychological history of our species, unless it could be shown that when the transition takes place in the psychological history of the individual, it does so in such a sudden and remarkable manner as of itself to indicate that the intellect of the individual has there and then undergone a change of kind. * * * * * Such being an outline sketch of my argument, I will now proceed to fill in the details, taking in historical order the various stages of ideation which I have named—_i.e._ the receptual, the pre-conceptual, and the conceptual. Seeing that this is, as I apprehend, the central core of the question, I will here furnish some additional instances of receptual and pre-conceptual ideation as expressed by denotative and connotative signs on the part of a child which I carefully observed for the purpose. At eighteen months old my daughter, who was late in beginning to speak, was fond of looking at picture-books, and as already stated in a previous chapter, derived much pleasure from naming animals therein represented,—saying _Ba_ for a sheep, _Moo_ for a cow, uttering a grunt for a pig, and throwing her head up and down with a bray for a horse or an ass. These several sounds and gestures she had been taught by the nurse as noun-substantives, and she correctly applied them in every case, whether the picture-book happened to be one with which she was familiar or one which she had never seen before; and she would similarly name all kinds of animals depicted on the wall-paper, chair-covers, &c., in strange houses, or, in short, whenever she met with representations of objects the nursery names of which she knew. Thus there is no doubt that, long before she could form a sentence, or in any proper sense be said to speak, this child was able to denote objects by voice and gesture. At this time, also, she correctly used a limited number of denotative words significant of actions—_i.e._ active verbs.