In the dog or the ape the rope is presumably incomparably simpler. But that it is of the nature of a rope we may, perhaps, not improbably surmise. Interest and the attention it commands steady the rope. Animals differ widely in their power of attention, as every one knows who has endeavoured to educate his pets. Darwin tells us that those who buy monkeys from the Zoological Gardens, to teach them to perform, will give a higher price if they are allowed a short time in which to select those in which the power of attention is most developed. And when animals dream, their consciousness-rope is slipping round unsteadily. That they do apparently dream is, so far, evidence of their possessing linked chains of memories. In speaking of the faculty of attention in animals, it may be well to note that attention is of two kinds--perceptual or direct, and conceptual or indirect. In perceptual attention its motive is directly suggested by the object which stimulates this concentration of the faculties; a menacing dog, for example, stimulates my perceptual attention. In conceptual attention the motive is ulterior and indirect. The concentrated attention which a man devotes to the acquisition of Sanscrit does not arise directly out of the symbols over which he pores; it is of intellectual origin. In the normal life of animals the attention is of the perceptual order; it is a direct stimulation of the faculties through a perceptual presentation of sense or representation in memory which gives rise to an appetence or aversion. The importance of such a faculty is obvious. As M. Ribot well says, it is no less than a condition of life. The carnivorous animal that had not its attention roused on sight of prey would stand but a poor chance of survival; the prey that had not its attention roused by the approach of its natural enemy would stand but a poor chance of escape. The emperor moth that had not its attention roused by the scent of the virgin female would stand but a poor chance of propagating its species. We are not, however, at present in a position further to discuss this matter. For there is a factor in the process which we shall have to consider more fully hereafter--the emotional factor. The hungry lion is in a very different position, so far as attention is concerned, from the satiated animal. The force and volume of the attention depends not merely, or even mainly, upon the intensity of the stimulus, but on the emotional state of the recipient organism. Endeavour to divert the attention of any animal which is intent upon some action connected with the main business of its life--nutrition, self-defence, or the propagation of the species--the force of attention will at once be obvious.