Mendelism

Abstract

IN reviewing a new edition of a book so well known as Prof. Punnett's “Mendelism,” it is unnecessary to notice more than the changes that have been made as compared with previous editions. The third edition (1911) was, in fact, a new book, and the fourth (1912) was substantially similar, with a certain amount of revision. Seven years have now passed, and although the war seriously interfered with genetic research in Europe, great progress in certain directions has been made in America, and it is to incorporate this new work that the chief changes in the present edition have been made. The first eight chapters are substantially unchanged, and comparatively little alteration has been made in the chapters on the economic aspect of genetics, on variation and evolution, and on man. To the chapter on intermediates there has been added an account of Nilsson-Ehle's theory of multiple factors as illustrated by his work on colour factors in wheat, by Davenport's work on mulattoes, and by Prof. Punnett's own work on the size-inheritance of fowls. Some special cases, such as that of doubleness in stocks, that were mentioned under various headings in previous editions are collected together into a special chapter on “Certain Complications.” We note with regret that the hypothesis of “multiple allelomorphs,” as illustrated by Nabours' experiments on grasshoppers and by certain characters in Drosophila—a hypothesis regarded by many as a preferable alterna-tivfe to the presence-and-absence theory—is no-where fully discussed.

Mendelism.

By Reginald Crundall Punnett. Fifth edition. Pp. xv + 219 + vii plates. (London: Macmillan and Co., Ltd., 1919.) Price 7s. 6d. net.