The animals do not have to consult the almanac to know when to migrate or to go into winter quarters. At a certain time in the fall, I see the newts all making for the marshes; at a certain time in the spring, I see them all returning to the woods again. At one place where I walk, I see them on the railroad track wandering up and down between the rails, trying to get across. I often lend them a hand. They know when and in what direction to go, but not in the way I should know under the same circumstances. I should have to learn or be told; they know instinctively. We marvel at what we call the wisdom of Nature, but how unlike our own! How blind, and yet in the end how sure! How wasteful, and yet how conserving! How helter-skelter she sows her seed, yet behold the forest or the flowery plain. Her springs leap out everywhere, yet how inevitably their waters find their way into streams, the streams into rivers, and the rivers to the sea. Nature is an engineer without science, and a builder without rules. The animals follow the tides and the seasons; they find their own; the fittest and the luckiest survive; the struggle for life is sharp with them all; birds of a feather flock together; the young cowbirds reared by many different foster-parents all gather in flocks in the fall; they know their kind--at least, they are attracted by their kind. A correspondent asks me if I do not think the minds of animals capable of improvement. Not in the strict sense. When we teach an animal anything, we make an impression upon its senses and repeat this impression over and over, till we establish a habit. We do not bring about any mental development as we do in the child; we mould and stamp its sense memory. It is like bending or compressing a vegetable growth till it takes a certain form. The human animal sees through the trick, he comprehends it and does not need the endless repetition. When repetition has worn a path in our minds, then we, too, act automatically, or without conscious thought, as we do, for instance, in forming the letters when we write.