>(1) Anatoxin-a is one bad dude.  It kills mice in microgram
> quantitites.

I would add that some of the most potent toxins known to man are
produced by micro-organisms, particularly those that live on
decaying produce.  There is a reason for this, in that it is to the
advantage of these species to kill off larger competitors to their
food supply.  Botulism, gray molds on breads, aflatoxin (widespread
on peanuts, corn & other crops which are harvested in warm, humid
climates) & other such nasties either can kill outright or are
powerful carcinogens.

--Doug Schwartz
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