POISONOUS PLANTS IN GENERAL 221 
less 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. 
4, Place no confidence whatever in any “rules” for telling 
poisonous from harmless species. te 
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 en- 
tirely harmless, unless with the approval of your physician. 
1Jn later chapters the student will be helped to recognize the more 
important families of plants, and will learn which of them consist en- 
tirely 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 harmkess species 
with suspicion. 
