its thin sheet of upland leaf-mold. By this simple plan the willow manages to get protection in winter, on the same principle as when we human gardeners lay down the stems of vines; only the willow remains laid down all the year and always. But in summer it sends up its short-lived herbaceous branches, covered with tiny green leaves, and ending at last in a single silky catkin. Yet between the great weeping willow and this last degraded mountain representative of the same primitive type, you can trace in Europe alone at least a dozen distinct intermediate forms, all well marked in their differences, and all progressively dwarfed by long stress of unfavorable conditions.
From the combination of such unfavorable conditions in arctic countries and under the snow-line of mountains there results a curious fact, already hinted at above, that the coldest floras are also, from the purely human point of view, the most beautiful. Not, of course, the most luxuriant: for lush richness of foliage and "breadth of tropic shade" (to quote a noble lord) one must go, as every one knows, to the equatorial regions. But, contrary to the common opinion, the tropics, hoary shams, are not remarkable for the abundance or beauty of their flowers. Quite otherwise, indeed: an unrelieved green strikes the key-note of equatorial forests. This is my own experience, and it is borne out (which is far more important) by Mr. Alfred Russel Wallace, who has seen a wider range of the untouched tropics, in all four hemispheres—northern, southern, eastern, western—than any other man, I suppose, that ever lived on this planet. And Mr. Wallace is firm in his conviction that the tropics in this respect are a complete fraud. Bright flowers are there quite conspicuously absent. It is rather in the cold and less favored regions of the world that one must look for fine floral displays and bright masses of color. Close up to the snow-line the wealth of flowers is always the greatest.
In order to understand this apparent paradox one must remember that the highest type of flowers, from the point of view of organization, is not at the same time by any means the most beautiful. On the contrary, plants with very little special adaptation to any particular insect, like the water-lilies and the poppies, are obliged to flaunt forth in very brilliant hues and to run to very large sizes in order to attract the attention of a great number of visitors, one or other of whom may casually fertilize them; while plants with very special adaptations, like the sage and mint group, or the little English orchids, are so cunningly arranged that they can not fail of fertilization at the very first visit, which of course enables them to a great extent to dispense with the aid of big or brilliant petals. So that, where the struggle for life is fiercest and adaptation most perfect, the flora will on the whole
