What is causal agent?

Some articles on causal agent, agents:

Newcastle Disease - Causal Agent - Use As A Biological Weapon
... Newcastle disease was one of more than a dozen agents the United States researched as potential biological weapons before the nation suspended its biological weapons program ...
Trichoderma - Causal Agent of Disease
... harzianum biotype 4) is the causal agent of green mold, a disease of cultivated button mushrooms ... Trichoderma viride is the causal agent of green mold rot of onion ...

Famous quotes containing the words agent and/or causal:

    The childless experts on child raising also bring tears of laughter to my eyes when they say, “I love children because they’re so honest.” There is not an agent in the CIA or the KGB who knows how to conceal the theft of food, how to fake being asleep, or how to forge a parent’s signature like a child.
    Bill Cosby (20th century)

    There is the illusion of time, which is very deep; who has disposed of it? Mor come to the conviction that what seems the succession of thought is only the distribution of wholes into causal series.
    Ralph Waldo Emerson (1803–1882)