VARIATION, HEREDITY, AND EVOLUTION.
Variation, Heredity, and Evolution. By R. H. Lock, M.A., Fellow of Gonville and Caius Colleges, Cambridge. (John Murray. 7s. 6d. net.)—Mr. Lock's guide to the views and con- troversies of the day regarding the habits and operations of Nature which give rise to the progressive changes in animal and vegetable life known as evolution would be of greater value to "the general reader" if his powers of exposition were on the level of his knowledge of Menders experiments on pea-flowers and maize, and of the algebraical scheme of heredity obtained by Cuenot from his studies of albino mice. But it is not so : the beginner may digest expressions like "germ-cell," but he will be frightened off by the recurrence of such terms as " gametes." " allelomorphs," and " zygobes," and other beauties of nomenclature which might have been translated into the vernacular. The author is no Miss Agnes Clerke ; but ho is at his best in his somewhat discontinuous sketches of the history of the idea of "mutation "—i.e., evolution —in the Aristotelian sense, and when he shows how Lamarck's fertile acorn of biological speculation, growing up half-a-century later into the spreading oak of Darwinism, was the germ of one of the loftiest forests of modern scientific inquiry. Lamarck was giving a positive, though crude, anticipation of Darwin when he taught that the snake's primeval ancestor was a four-legged beast like, perhaps, a cat or a cow, who in trying to pass through narrow crevices got squeezed into an elongated shape inherited by his descendants. So also the early giraffes had short necks. which they stretched by browsing on the leaves of tall trees, while the secret of the long legs of wading birds might be traced to the dislike of their remote parents to wetting their feathers when picking up fish in shallow water. Mr. Galton's statistical studies of variation and eugenics will be better examined in his books, or in the Gower Street laboratory that bears his name ; his curves and quasi-thermometer readings of strength of pull and differences of stature in families are reproduced, but not elucidated, by Mr. Lock. A relative novelty of this volume is the elaborate account of the work of the Abbot Mendel of Briinn, whose cross-breeding experiments with peas started what may be called the non-empirical, labora- tory methods of modern biological study. Readers with memories of Vienna bread, or even of its inferior German imitations, may like to hear that the things we call loaves and rolls are what they are because, while Free-trade does not help the baker, the wheat required for high-quality bread cannot be grown in England at a profit, but that, thanks to the Cambridge Experimental Farm, new types of corn have been grown which may be cultivated with great advantage to the farmer's pocket ; also that a still more important achievement of the Ul‘iversity farm is the production of strains of wheat enjoying complete immunity from the fungus known as "yellow rust," the ravages of which cost the corn countries annual losses reckoned at many millions. Looking beyond our volume, we desire personally to explain that the University experiments have been carried on with wheat, barley, and mangels, and to a smaller extent with other crops ; several new varieties of seed will be ready for distribution next autumn. This work is, of course, entirely beyond the practical breeder, but the Institute was inspected last summer by about six hundred farmers and others interested, and there will be a large demand for seed of the new varieties when they are ready for distribution. The preliminary work is carried on in the University, where a special department for agricultural purposes is to be established. The Mendel system pursued at the Cambridge farm patronises sheep as well as cereals, and Mr. Bateson and other devotees of " genetics " are half hoping that as our century has created improved grain and rams, it may be able to generate types of humanity in new forms of "native worth and beauty clad." Time well- known hierophant of advanced "biometry," Professor Pearson, has demonstrated, so we read, that "a steady breeding out of intelligence is taking place" in our professional and middle classes, so that if our national greatness is to be saved, recourse must be taken to more stringent methods than mere education
and gymnastics. Our author seems to adopt this view, and he quotes from Mr. Bernard Shaw rhetorical proofs that our "promiscuous breeding" has produced a race of cowards and sluggards, who "neglect artificial selection under cover of delicacy and morality," so that the " Superman " (the party borrowed by Mr. Shaw from Nietzsche) is not likely to arrive at present.
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