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 si)ecies 

 highly valued for food.' 



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 l)e 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. 



^ In 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 harmless species 

 with suspicion. 



