I notice that certain of the wood-folk--mice and squirrels and birds--eat mushrooms. If I would eat them, I must learn how to distinguish the edible from the poisonous ones. I have no special sense to guide me in the matter, as doubtless the squirrels have. Their instinct is sure where my reason fails. It would be very interesting to know if they ever make a mistake in this matter. Domestic animals sometimes make mistakes as to their food because their instinct has been tampered with and is by no means as sure as that of the wild creatures. It is said that sheep will occasionally eat laurel and St. John's-wort, which are poisonous to them. In the far West I was told that the horses sometimes eat a weed called the loco-weed that makes them crazy. I have since learned that the buffaloes and cattle with a strain of the buffalo blood never eat this weed. The imitation among the lower animals to which I have referred is in no sense akin to teaching. The boy does not learn arithmetic by imitation. To teach is to bring one mind to act upon another mind; it is the result of a conscious effort on the part of both teacher and pupil. The child, says Darwin, has an instinctive tendency to speak, but not to brew, or bake, or write. The child comes to speak by imitation, as does the parrot, and then learns the meaning of words, as the parrot does not. I am convinced there is nothing in the notion that animals consciously teach their young. Is it probable that a mere animal reflects upon the future any more than it does upon the past? Is it solicitous about the future well-being of its offspring any more than it is curious about its ancestry? Persons who think they see the lower animals training their young consciously or unconsciously supply something to their observations; they read their own thoughts or preconceptions into what they see. Yet so trained a naturalist and experienced a hunter as President Roosevelt differs with me in this matter. In a letter which I am permitted to quote, he says:--