1 DECEMBER 1928, Page 15

How lar.the world's wealth may be increased by the prods

that. science gives.to. evolution is an engaging subject.. There are men alive who have. worked long enough. to test results. They have done an aeon's work within a generation or two. For example,. an octogenarian poultry-breeder showed. me convincing evidence that he and.his kind had added .not less than 2f lbs. to the.weight of a Christmas turkey born the same year. They have done for the turkey what racing specialists have- done .for. the thoroughbred, only they have increased the size -more quickly. All animals are being graded up ; and most good-plants. But with plants it is easier to improve quality than yield. The newer potatoes for example, have many virtues—in flavour and disease resistance—but the actual bulk of-produce is often rather less than more.