The Resting Position of the Oyster—A Correction

Abstract

IN a late number of NATURE (vol. xxxii. p. 597) Mr. J. T. Cunningham makes the extraordinary announcement that Wood-ward, Jeffrey, and Huxley were wrong in asserting that the oyster rests on the left side. I am in a position to state with positive certainty that it is invariably the left valve of the fry of the oyster which becomes affixed to a foreign object. I have examined thousands of very young adherent spat ranging in size from 1–90th of an inch to 2 inches in diameter, and have never found an exception to this rule. Besides the positive statements to the same effect made by Huxley and others, I would refer the reader to a brief paper by myself entitled “On the Mode of Fixation of the Fry of the Oyster” (Bull. U.S. Fish Commission, vol. ii., 1882, pp. 383–387); but I would caution the reader that Figs. 3 to 8 were reversed through an unfortunate oversight, as the apices of the umbos of all the larval shells figured on p. 387 should be directed to the left instead of to the right side. This blunder of the artist is pointed out in the explanation to plate 75, where the figures from the above-cited notice are reproduced in my paper entitled “A Sketch of the Life-History of the Oyster,” forming Appendix II. to “A Review of the Fossil Ostreidre of North America,” by Charles A. White, M.D., and Prof. Angelo Heilprin. In another paper of mine, “The Metamorphosis and Post-Larval Development of the Oyster,” Rep. U.S. Fish Commissioner, Part 10, for 1882, p. 784, Fig. 2 shows the larval shell, L, of the young spat in normal position, with the umbo directed to the left. This figure may be compared with advantage in respect to the points raised here with the figure of the external anatomy of the adult on plate 73 in my “Sketch of the Life-History of the Oyster,” already cited.