We often say, for example, that _interest_ guides behaviour in this direction or in that. But such interest must not be regarded as an impelling force; it is an attribute of the conscious situation, more or less suffused with feeling-tone. It is not easy to define; but it seems to take on its distinctive character when re-presentative elements contribute what Dr. Stout[121] terms “meaning” to the conscious situation. The meaning in the early stages of mental development is, however, merely perceptual, and not that which comes much later--that which is implied in the phrase “rational significance.” In the chick which has tasted a cinnabar caterpillar the situation evoked by the sight of this larva has meaning in virtue of the actual experience. But, in this case, the meaning is not conducive to continued interest, since it checks, rather than stimulates, behaviour. At first, indeed, there may be the repellent interest of aversion. But this passes by, and the larvæ are soon ignored. Small worms also acquire meaning, and here the interest is attractive, and is stimulated afresh each time the meaning is reinforced by repetition of the act of seizing and swallowing. We have seen that it is through behaviour that things become differentiated from their surroundings, and acquire relative independence in experience. It is through behaviour that what we have termed conscious situations develop. The thing is the centre or nucleus of a developing situation--that which starts the behaviour, and towards which the behaviour is directed; or, since the behaviour may be that of avoidance or escape, we should, perhaps, rather say, it is that to which the behaviour has reference. Now, if interest is the feeling-tone attaching to the whole attentive situation, and if the nucleus of the situation is the thing, it naturally follows that the thing becomes the centre of interest. The mouse is a centre of absorbing interest to the cat, her eggs to the mother-bird, his mate to the sparrow in the spring. Companions are centres of abiding interest to social animals, because they are also the centres of social behaviour and the conscious situations arising thereout; because they evoke in special ways the attentive situation.