_Lithospermum Prostratum._—If we were only allowed one rock plant out of all there are, we would choose this one. It flowers nearly all the year round in some parts of England, and its blue is as vivid as the blue of a Gentian. If you can plant it so that its roots can tuck themselves under a big rock as they grow, so much the better. We have transplanted a big plant of it successfully, but we did it in fear and trembling, as it is said to hate disturbance. You had better not try to divide it. It can only be increased by cuttings, and they are not at all easy to strike. _Phlox Setacea._—This is one of several varieties of dwarf Phloxes that are useful for edgings and rockeries. They must have sun and well-drained soil, or they damp off. _Speedwell: Veronica Repens._—There are many varieties and sizes of Veronica. Some make big garden shrubs. The one we recommend here is a tiny trailing plant, with small pale blue flowers. It increases at a great rate, and is easily divided. Slugs like it, but do not make headway against it in many gardens. It makes a pretty dwarf edging amongst stones, as it creeps amongst them, and partly covers them. [Illustration: “THE ROAD TO ROME.”] _The Sedums, Saxifrages, and House-leeks, or Sempervivums_, are all suitable for rockeries. Some kinds of Sedums, or Stonecrops, grow wild in our hedges. You should get Sedum Spectabile, the Japanese Stonecrop, which bears large heads of pink flowers in August. There are many widely differing varieties of Saxifrage, or Rockfoil; for instance, Muscoides, the Mossy Saxifrage, makes a plump, low cushion of green moss on your rockery; Sarmentosa is the well-known weed, Mother of Thousands; Umbrosa is London Pride. Some have large leaves and pink flowers; some send up pyramids of white flowers from tufts of silvery leaves. You must grow one or two at a time, and get to know them by degrees. Sempervivums are those little green rosettes you see spreading in clumps on old roofs and walls. One of the most fascinating is Sempervivum Arachnoideum, the Cobweb House-leek. It covers itself with a curious white down that looks like a spider’s web. They like a dry sandy part of the rock garden, and full exposure to the sun.