clearly as red and yellow. Magnus hypothesized that the process may still be ongoing, so that in future centuries the retina will extend its sensitivity to ultraviolet light as well.
Magnus’s theory became one of the most ardently discussed scientific questions of the day and received support from a range of prominent figures in different disciplines. Friedrich Nietzsche, for instance, integrated the color blindness of the Greeks into his philosophical edifice and drew from it fundamental insights about their theology and worldview. Gladstone, now an ex–prime minister and at the height of his fame, was gratified to find a scientific authority so enthusiastically championing his findings of twenty years earlier and wrote a favorable review in the popular journal
The Nineteenth Century
, which ensured that the debate spilled over to other popular magazines and even the daily press.
The claim that the color sense evolved only in the last millennia also received a considerable amount of support from eminent scientists, including some of the brightest luminaries in the evolutionary movement. Alfred Russel Wallace, the codiscoverer with Darwin of the principle of evolution by natural selection, wrote in 1877 that “if the capacity of distinguishing colours has increased in historic times, we may perhaps look upon colour-blindness as a survival of a condition once almost universal; while the fact that it is still so prevalent is in harmony with the view that our present high perception and appreciation of colour is a comparatively recent acquisition.” Another stellar convert was Ernst Haeckel, the biologist who had proposed the theory that an embryo recapitulates the evolutionary development of the species. In a lecture to the Scientific Club of Vienna in 1878, Haeckel explained that “the more delicate cones of the retina, which impart the higher color-sense, have probably developed gradually only during the last millennia.”
THE NECK OF THE GIRAFFE
Looking back at Magnus’s theory from today’s vantage point, we cannot but wonder how such eminent scientists could have failed to pick upon the various rather odd things about it. But we have to put ourselves in the mind-set of the late nineteenth century and remember that much of what we take for granted nowadays, for instance about the physics of light or the anatomy of the eye, was a complete mystery to scientists just over a century ago. The distance between us and Magnus’s contemporaries is even greater in all that concerns knowledge of biological heredity, or, as we call it today, genetics. And, since heredity is the pivot of the whole debate over language’s place between nature and culture, if we are to understand this debate, we need to pause for a moment and try first to jump over the gap of imagination that separates us from the 1870s. This task is far from easy, since the gap is about as long as the neck of the giraffe.
We are all acquainted with the logic of “just so” stories: the giraffe got his long neck because his ancestors stretched and stretched to reach higher branches, Kipling’s elephant got his long trunk because the crocodile pulled his nose until it stretched and stretched, and Ted Hughes’s lovelorn hare got his long, long ears from listening and listening, all through the night, for what his beloved, the moon, was saying high in the sky. Today’s children realize at a fairly early stage that all this is only fireside fable. The main reason why the logic of such stories is confined to the nursery is a truth so universally acknowledged that hardly anyone even bothers to state it explicitly nowadays. This is the understanding that physical changes you undergo during your lifetime will not be passed on to your offspring. Even if you do manage to stretch your neck, like the Padaung women of Burma with their neck rings, your daughters will not be born with longer necks as a result. If you spend hours on end lifting weights, this will