BLUE flowers are the least plentiful, and the philosophers tell us the reason why. All flowers, they say, were at first green; from this they diverged to yellow and white; their next advance was to shades of red. Their triumphant colour--or, say, their final stage in chromatic evolution-is blue. If we accept the hypothesis--for theory it is not--we must regard the gentians as incapable of further change in respect of colour; they have passed through all the prescribed phases, and having reached the goal, may rest and be thankful, while myriads of flowers in the earlier stages are still slowly fighting their way to the "blue ribbon" of the turf amidst which they sparkle and glow.

Gentians rank amongst the noblest of Alpine flowers, and they give us tones of blue that never fail to excite surprise, no matter how familiar we may be with them. Their geographical range is certainly South European; but their head-quarters are the mountains that run east and west from Transylvania to Cape Finisterre. India, too, has its true gentians and its exacums, these last being marvels of colour--the petals intensely blue, and the stamens intensely yellow.

Conjuring is easy when you know how to do it; and so also is the growing of gentians. It is given to few to succeed, while many fail, and our business in these pages is to point out the way to success for any and every lover of these much-loved flowers. Go with us up the mountain, and you shall see them in the pastures, and in nooks amongst the rocks, where they are exposed to the fullest light, and are frequently bathed in mountain moisture. You will never see them in a dry soil; you will never see them in such shaded hollows as the ferns creep into; and you will not often see them where keen breezes prevail. They like sheltered nooks, open to all the light of heaven and to the kindlier airs of the mountain; and their roots must have constant supplies of moisture, or the plants will surely fade away. These conditions may all be secured in gardens; and as a matter of fact, all the gentians are well grown in gardens by the few--it is with no pleasure we say the very few--who know how to do it.

The gentianella (Gentiana acaulis) is one of the easiest to manage as a garden plant, but is useless on a very dry soil. A deep moist loam will suit it well, and a surfacing of stones seems always to its taste; in fact, a stony soil, deep and moist, will suit this and many more of the gentian family. We have seen this flower employed with excellent effect as an edging, its compact tufts of deep green leaves rendering it a quite respectable plant. Its usual place is the rockery, for which it is so well adapted that if only a score of rock plants are wanted, the gentianella should be one of them. The custom of planting little mites of plants we shall not object to, because the planter must have freedom of action when the purse is appealed to; but we are bound to say that a small tuft of this beauty is never sufficient for its vindication as the perfection of a rock plant. A few large patches or carpets are required, and it is easy to obtain them by sowing the seeds every year in pans in a frame, and nursing the young plants carefully, remembering also that they are perfectly hardy, and are more in need of protection against drought than against frost or wind or sun.

The spring gentian, or Gentiana verna, is the proper companion to the gentianella. It will generally thrive in the same soil, and both will sometimes display a vagrant quality in spreading from the comfortable bed prepared for them to the adjoining gravel-walk, in which, if allowed, they will run riot, as if to show how they love to be in contact with stones. The vernal gentian, however, needs a moist, sandy soil, and it is an advantage if smallish pieces of sandstone are mixed with it; but moisture is before all things important, the sure result of dryness at the roots during May and June being the death of the plants. In a soil they like they root deeply, and the stones on the surface check evaporation and help to sustain the plant by the retention of moisture.

The Bavarian gentian (G. Bavarica) is like the vernal gentian, but has fewer leaves, and the flower-stems are thickly clothed with a leafy setting for its brilliant blue flowers. This requires boggy soil, and in making a bed for it, spongy peat should be selected.

The swallowwort gentian (G. asclepiadea) is a freegrowing, herbaceous plant, bearing blue or white flowers on long leafy sprays. It will thrive in a moist loam or peat, and appears always to be happiest when slightly shaded.

The crested gentian (G. septemfida) is a very fine plant, of moderate growth; the flowers are set in clusters, the colours being blue and white within, and greenish-brown without, while the alternate petals are finely fringed. This gentian requires moist, sandy peat.