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:

    I wish not to be given a title or an appointed position. I can and will do more good if I were made a Federal Agent at Large, and I will help best by doing it my way through my communications with people of all ages. First and Foremost I am an entertainer but all I need is the Federal Credentials.
    Elvis Presley (1935–1977)

    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)