As worms are not controlled by special instincts in each particular case, though possessing a general instinct to plug up their burrows, and as chance is excluded, the next most probable conclusion is that they try in many ways to draw in objects and finally succeed in some one way. It is surprising, however, that an animal so low in the scale as a worm should have the capacity to act in this way, as many higher animals have no such capacity, the instincts of the latter often being followed in a senseless or purposeless manner. We can safely infer intelligence, as Mr. Romanes, who has specially studied animals, says, only when we see an individual profiting by his own experiences. That worms are able to judge either before or after having drawn an object close to the mouths of their burrows how best to drag it in, shows that they must have acquired some notion of its general shape. This they probably acquire by touching it in many places with the anterior extremity of their bodies, which serves them as a tactile organ. Man, even when born blind and deaf, shows how perfect the sense of touch may become, and if worms, which also come into being in the same condition, have the power of acquiring some notion, however rude, of the shape of an object and their burrows, they deserve, it must seem to every sensible mind, to be called intelligent creatures, for they act in such a case in nearly the same manner as a man would under similar circumstances. That worms, which stand so low in the scale of organization, should possess some degree of intelligence, will doubtless strike everyone as very improbable. It may be doubted, however, whether we know enough about the nervous system of the lower animals to justify our natural distrust of such a conclusion. With regard to the small size of the cerebral ganglia, we would do well to remember what a mass of inherited knowledge, with some power of adapting means to an end, is crowded into the minute brain of a worker ant.