AMERICAN JOURNAL OF OPHTHALMOLOGY
mechanism of visual transduction more precisely. Although understanding the mechanism of visual transduction is an important subject in its own right, the chapter by G. J . Chader and associates on earlyonset inherited retinal degeneration will be of particular interest to clinical ophthalmologists. This work relates studies of retinal metabolism to possible mechanisms of retinal dysplasia in several animal models and shows the clinical implications of understanding visual transduction. The mechanism of visual transduction is a challenging and fascinating subject, clearly one of the central problems in vision science. The contributors to this volume have also made significant contributions to the understanding of visual transduction through their experimental work in the laboratory. Here, they review their own work in the light of more recent experimental information and theoretical concepts. Thus, this is not a book to let sit on the shelf. It is highly recommended for anyone interested in obtaining a thorough overview of current thinking in this field.
editions and as medical books go they are both reasonably priced and a good buy. Neither dictionary can really justify calling itself "illustrated." On the average, you have to turn 3.2 pages in Stedman's before you come to another in-text illustration and 6.1 pages in Dorland's. If you want to see what an illustrated medical dictionary looks like, check Melloni's (Baltimore, Williams and Wilkins, 1979); it has 4.7 clear illustrations on each of 529 pages, but only one-fourth the number of entries. Ever since Dr. Johnson's famous dictionary came out in 1755 every lexicographer has kept his own master citation file showing how words have been used by various writers and speakers in the past. This file is the foundation of any dictionary's scholarly authority. Nowadays the file is handled by a computer, a machine that can also do all the mechanical chores like sorting, alphabetizing, and classifying. One doesn't have to look far beyond the horizon to anticipate the day when we will turn to the computer to look up a word. It is as easy to type the word into the computer as it is to turn to the appropriate page in a dictionary. Each of these two volumes is the modern repJOSEPH F . METCALF resentative of a long line of medical dictionaries—Stedman's goes back to 1833 and Dorland's to 1901—but the series may one day come to an end and be Stedman's Illustrated Medical Dictionary, replaced by a few microchips in your 24th ed. Baltimore, Williams & Wilkins home computer. I don't particularly look Company, 1982. Hardcover, 1,678 forward to that day; I like to riffle through pages, illustrated, thumb-indexed. the pages and stop where something $33.50 catches my eye. It would be harder to browse through a computer file. Dorland's Illustrated Medical Dictionary, 26th ed. Philadelphia, W. B. Saunders Co., 1981. Hardcover, 1,485 pages, illustrated, thumb-indexed. $37.50
Both of these standard medical dictionaries have recently come out with new
Dorland's has slightly larger pages and larger and cleaner type, but it is 20% heavier. The readability of both dictionaries is excellent: symbols, abbreviations, and dictionary shorthand are kept to a minimum. Each dictionary is equipped with a valuable essay on medical etymolo-