HYBRIDS of the more showy species of clematis are now so numerous as to constitute a distinct and large class of garden flowers. The parents of these many splendid varieties, of which Clematis patens, C. lanuginosa, C. viticella, and C. Fortunei may be named as having afforded the strongest characters, are for the most part traceable in them by the eye of an expert; but it happens that in a majority of instances the pedigrees have been preserved, and therefore a collection of clematis may be studied with advantage by the scientific botanist, as they may be by the lover of flowers, for the sake of their beauty only. The variety figured is one of the most interesting in the scientific and historical view of the subject. In the year 1835 Mr. Henderson, of the Pine Apple Nursery, London, raised a new hybrid, which was named in his honour Clematis Hendersoni. It was believed to be the result of a cross between C. viticella and C. integrifolia. This "Henderson's clematis" is a fine climber, running ten to fifteen feet, and producing an abundant display of large handsome flowers of a purplish-blue colour. One of the grandest natural species (as distinguished from garden varieties) is Clematis lanuginosa. This produces flower of immense size, the colour a soft lavender-blue or lilactinted grey, which is enriched with a tuft of reddish anthers. This plant does not flower so freely or so continuously as to satisfy the exigent florists, and the question has arisen, What can we do to improve it?

In the year 1858 Mr. George Jackman, of the Woking Nurseries, made an endeavour to meet that question, and extraordinary results have followed therefrom. He crossed C. lanuginosa with C. Hendersoni, and obtained two new and splendid varieties, producing flowers remarkable for their richness of colouring, their excessive profusion, and their long continuance. Rarely in the history of practical floriculture have we seen so great a triumph accomplished at one bound. The two new sorts were named respectively C. Jackmanni and C. rubro-violacea. The first-named is certainly one of the most popular garden flowers known. The other, of which we present a faithful portrait, is less popular, but not less worthy of esteem; for its flowers are exquisitely coloured and lustrous, and are produced in the most prodigal profusion--in fact, a verandah well clothed with this clematis will present during the later summer months a display of colour of the most surprising and delightful character.

These two varieties have in their turn produced innumerable seedlings; and from other crosses, effected by various cultivators, there have been secured valuable additions to the list of garden forms of this hardy and useful flower. The free-growing sorts are amenable to the simplest treatment; but it should be said that they flower so freely that they must be well fed, or they will actually die out and give no account of themselves at all. They should be planted in well-prepared soil, consisting of good loam, liberally enriched with half-rotten manure--in fact, such a bed as would be prepared for climbing roses or wistarias; for plants that grow fast and far need to be well sustained at the root. These clematis, being planted in the spring, will probably run ten or twelve feet the same season, and will flower fairly well. The second year they will make a most vigorous growth and flower profusely. The third year they may be expected to do still greater things, and then they must have fresh food, or they will begin to travel down hill. If left alone they will still flower freely; but the flowers will become smaller year by year, and the plants will be bare of leaves except at the top. If still left without help they will dwindle away, and die at last through sheer exhaustion, unless indeed they happen to be peculiarly circumstanced as regards the food their roots can reach.

Thus we reach the second chapter in the management. When the plants are becoming "leggy" and the flower small, they should be cut down to within eighteen inches of the ground. This may be best done at the end of the year, or early in January. Some time in February, or early in March, remove the top soil from over the roots, but taking care to injure them as little as possible, and put in its place a mixture of half-rotten manure and fresh turfy loam; at the same time take out a trench two feet deep and one foot wide at a distance of two feet from the stem of each, and fill this with a similar mixture. Then spread over all a coat of fat stable manure, and leave the rest to nature, and you will be well rewarded in due time.

It is a matter of interest that hybrid clematis may be grown in beds, and in this case require to be trained over hoops to form a low convex shield-shaped mass of green leaves and gorgeous flowers. For this purpose the best are Jackmanni, with violet-purple flowers; Rubroviolacea, with maroon-purple flowers; Alexandra, reddish-violet; Magnifica, purple and red; Rubella, deep claret; Star of India, reddish-plum with red stripe; Tunbridgense, reddish-lilac with mauve stripe. Another use for them is as pillar plants, both in the garden and the conservatory; but when so grown out of doors, measures must be taken to prevent birds lodging on the tops of the pillars: sharp spikes will generally accomplish the purpose. Finally, when grown as round-headed bushes in tubs and pots they are superb adornments for the conservatory, the entrance hall, and the public exhibition.