Part 64. The preceding sections have shown that serious or even fatal consequences may result from eating, chewing, or sucking various parts of poisonous plants, or from overdoses of medicines prepared from them; that the juice of certain plants causes painful effects wherever it touches the skin; and that merely handling other kinds produces similar effects with certain persons. We have seen also that the number of common plants, both wild and cultivated, which are poisonous in one way or another is much larger than is generally realized. The practical conclusions to be drawn from these facts are surely very plain, but as they cannot be too strongly emphasized it may be useful to embody them in the following summary:-

1. Never put into the mouth any part of any plant with which you are not perfectly well acquainted and know to be harmless beyond the possibility of a doubt.

2. Be especially cautious with regard to plants which are young or show only young spring shoots, or which have not come into blossom or fruit; for the younger a plant is, or the fewer parts it displays, the more easily it may be mistaken for some other kind.

3. Be suspicious of all plants which resemble those known to be poisonous; for such resemblance is likely to indicate relationship, and plants closely related are apt to possess similar properties. But never suppose a plant to be harmless simply because it bears a general resemblance to certain well-known harmless species; for some of the most poisonous plants very closely resemble and are nearly related to species highly valued for food.1

4. Place no confidence whatever in any "rules" for telling poisonous from harmless species.

5. Do not suppose that plants which are harmless to birds, cattle, or other animals, may not be poisonous to human beings; for many plants which are poisonous to us are eaten by various animals with impunity.

6. Learn to recognize at sight the species of your locality which are poisonous to handle. If possible get some one who knows the plants to point out specimens to you in the field, and show you the features by which they may be always recognized. Then let him test your knowledge on the matter to see if the characteristics of each species are firmly impressed on your mind. If you find you know well all the dangerous species you will feel safe in handling any others.

7. Never use medicines which you do not know to be entirely harmless, unless with the approval of your physician.

1 In later chapters the student will be helped to recognize the more important families of plants, and will learn which of them consist entirely or almost entirely of poisonous species, and which families are comparatively harmless. Until he is able to classify the plants about him as to their families and is well informed regarding the extent to which relationship may be depended upon to indicate similarity of properties, safety requires that he should regard many harmless species with suspicion.