The definitions used in this glossary of terminology either have been provided by the authors of the articles, or have been extracted wholly or in part, or paraphrased from the following sources: The American Medical Association Encyclopedia of Medicine, Charles B. Clayman, MD, Medical Editor, Random House, New York, 1989; Biotechnology from A to Z, 2d Edition, William Bains, Oxford University Press, New York, New York, 2002; A Dictionary of Genetics, 6th Edition, Robert C. King and William D. Stansfield, Oxford University Press, New York, New York, 2002; Dorland's Illustrated Medical Dictionary, 29th and 30th Editions, W. B. Saunders Company, Philadelphia, 2000, 2003; Genes VII, Benjamin Lewin, Oxford University Press, New York, New York, 2000; The Gale Encyclopedia of Genetic Disorders, Volumes I and II, Stacey L. Blachford, Ed., Thomson Learning, New York, New York, 2002; The Merriam-Webster Dictionary, Merriam-Webster, Inc., Springfield, Massachusetts, 1997; Molecular Biology of the Cell, 3rd Edition, Bruce Alberts, et al., Garland Publishing, 1994; The Random House Dictionary of the English Language, Unabridged Edition, 1966; Webster's Ninth New Collegiate Dictionary, 1991.

DEFINITION:

cone

1. A solid figure or body with a circular base tapering to a point; called also conus.

2. Retinal cone.

3. In radiology, a conical or open-ended cylindrical structure attached over the portal of the x-ray tube housing, used as an aid in centering the radiation beam on the target field and as a guide to source-to-film distance; also, often designed to collimate primary and/or scattered radiation, and/or to retain disks for added filtration.

4. In root canal therapy, a solid substance with a tapered form, usually made of gutta-percha or silver, fashioned to conform to the shape of a root canal.

5. A marine snail of the family Conidae.