impenetrable nature of the glass plate and its position is not the least indication of lack of intelligence. In daily life we constantly see people do things they have observed injure them, and yet, in spite of experience, go and do the same again.
The glass experiment proves to me that the jack, like all other creatures, really has a latent power of intelligence beyond that brought into play by the usual circumstances of existence. Consider the conditions under which the jack exists—the jack we have been approaching so carefully. His limits are the brook, the ponds it feeds, and the ditches that enter it. He can only move a short distance up the stream because there is a high hatch, nor can he go far down because of a mill; if he could, the conditions would be much the same; but, as a matter of fact, the space he has at his command is not much. The running water, the green flags, the lesser fishes, the Avater-rats, the horses and cattle on the bank—these are about all the things that he is likely to be interested in. Of these only the water, the lesser fishes, the flags, and the bottom or sides of the brook, are actually in his touch and complete understanding. As he is unable to live out of water, the horse on the bank, in whose very shadow he sometimes lies, might be a mile away for aught it concerns him. By no possible means can he discover anything about it. The horse may be itself nothing more than a shadow, unless in a shallow place he steps in and splashes. Night and day he knows, the cool night, and the sunbeams in which he basks; but he has no way of ascertaining the nature of anything outside the
