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Rh slope of the escarpment is to a great extent covered with aboriginal turf, and it is in this portion that the rich growth of xerophilous calcareous plants is to be found. The comparatively short grass does not overshadow the flowering plants, so that in the early summer we have a very brilliant display of blossom, five distinct shades of yellow being the groundwork in the colour scheme, the deepest being struck by the dark orange-flowered horse-shoe vetch (Hippocrepis comosa) ; the next, but slightly more golden in tint, is caused by the lotus (L. corniculatus) ; then comes a somewhat greenish-yellow sheen where great patches of the golden stonecrop (Sedum acre) occur, and a very pale yellow is created where the lady's-fingers (Anthyllis Vulneraria) displays itself, but the paler tint is not altogether derived from the petals, but in part is caused by the conspicuous calyces, while the fifth species growing in countless thousands of pale-gold blossoms is the rock-rose (Helianthemum Chamcecistus) with its very fugacious petals ; and as if to vie with them the key-note is repeated in the cornfields, where closely contiguous masses of the white mustard (Brassica alba) glow with a vividness that is almost painful under the bright noonday sun. But there are other plants in the turf besides this chord of yellow-blossomed species ; there are the pinkish-white flowers of the squinancy-wort (Asperula cynanchica), the rosy-pink pyramidal spikes of the orchid (Orchis pyramidalis), or where a rather more impervious bed of chalk occurs we have the duller purple spikes of the fragrant orchid (Habenaria conopsea), and more sparingly the bee orchid (Opbrys apifera). Here and there the milkwort (Polygala vulgaris), with the flowers varying through different shades of blue to pink or white, may be seen, and it is a little curious and inexplicable why on the Berkshire downs the ubiquitous milkwort is P. calcarea, which here is extremely local and so much less frequent than the common one. Occasionally, especially on the downs above Ivinghoe, may be seen the yellow blossoms of the field ragwort (Senecio campestris), and not uncommonly the purple blue-flowered Canterbury bell (Campanula glomerata). In very many places bushes of the juniper (Juniperus communis) give a dark green colouring, and this too is exceedingly scarce on the Berkshire downs, although here so plentiful, and not restricting itself to the downs, but stretching inland to such commons as Naphill or Burn- ham Beeches, or the slopes near Medmenham. Bushes of the sweet brier (Rosa Eglanteria) and R. micrantha are plentiful near Princes Ris- borough and Wendover. Where the turf has been removed the porce- lain-white blossoms of the candytuft (Iberis amara) will probably be seen, and few of the arable fields on the bare chalk are without it. Bordering the beech woods may be seen the white blossoms of the helleborine (Cephalanthera pallens), and in the woodland shade the bird's- nest orchid (Neottia Nidus-avis), and the wall lettuce (Lactuca muralis). But we have not even yet exhausted the constituents of the turf, for the rather pretty grass Kæleria cristata is plentiful, as well as the more striking oat-grasses (Avena pubescens and A. pratensis), while the brome (Bromus erectus) is abundant. Later in the season the turf is studded