214 MEDICINAL AND POISONOUS PLANTS 
ous to suppose that one knows, when one does not know. It 
is indeed hardly safe for one who has not had good botanical 
training to depend upon even accurate pictures and descrip- 
tions of mushrooms; and it is decidedly unsafe for the average 
person to rely upon information gained from popular writings 
upon edible fungi. Not a few cases of poisoning within 
recent years have been traced to the misstatements in, or the 
misunderstanding of, attractive books or magazine articles 
on the subject. Another fertile source of danger is belief 
in the so-called rules ‘‘for telling a mushroom from a toad- 
stool,’’ such for example as the oft-repeated saying that a 
piece of silver placed in contact with mushrooms that are 
being cooked will turn black if they are poisonous. This and 
all similar rules are worse than worthless for not only is one 
led by them to regard as poisonous many edible forms, but 
some of the deadliest species might be called edible. Nothing 
less than thorough acquaintance with all the botanical char- 
acters which distinguish our common species at different 
ages can be relied upon to enable a person to tell the differ- 
ence between edible and poisonous mushrooms. There are 
no short cuts to such knowledge. The only really safe way 
for a beginner to learn about mushrooms with a view to eating 
them, is to be instructed by an expert botanist, in the field, 
or from fresh specimens. Until the student has learned 
the art of observing accurately he should distrust his own 
ability to determine specimens as edible with the aid of books 
alone. Meanwhile, it is desirable that he should learn some- 
thing about our two most poisonous species since the majority 
of fatal cases have been due to eating specimens of these or 
closely similar forms. The most deadly of all fungi is the 
death-cup (Fig. 205). Its name is derived from the fact 
that the stalk is enveloped at its base by a cup. Beware of 
any toadstool having such a cup. As the fungus presents an 
especially attractive appearance and has a pleasant flavor 
it has tempted many persons to their death. The symptoms 
of poisoning do not appear for a number of hours after the 
fungus has been eaten, and by that time so much of the poison 
has been absorbed into the system that recovery is hardly 
possible. Scarcely less poisonous, but more common is the 
