236 



THE GAEDENEE'S ASSISTANT. 



foot-stalk, or whatever part of it is left, should 

 be inserted, up to the base of the blade, in pure 

 white sand, laid over sandy peat, or other com- 

 post suitable for the growth of the plant after 

 the leaf has struck root. When the foot-stalk 

 is cut off close to the base of the blade, the 

 latter should be laid flat and the base part 

 slightly inserted in the sand, in which it should 

 be kept by a small peg or stone and covered 

 with a pane of glass or bell-glass, the edges of 

 which ought to be well pressed into the sand. 

 They should then be placed in the same tem- 

 perature as is required for stem-cuttings of the 

 same plant. The glasses must be shaded at 

 first, and the atmosphere kept moist. 



Buds are formed on the principal nerves as 

 well as on the midrib. It is therefore a good 

 plan to cut these nerves across in several places 

 without, however, severing the lamina. Thus 

 treated a single leaf is capable of producing a 

 large number of plants. Generally callus is 

 formed on the lower part of the severed por- 

 tion, and from this roots are emitted before any 

 leaf-bud is perceptible. Plants raised in this 

 way assume the juvenile character of seedlings. 

 They always, however, reproduce the peculiar 

 characters of the parent plant. Buds are, in 

 some cases, emitted from the indentations of 

 the margin, as in Bryophyllum p'oliferum. 



IX. — Propagation by Roots. 



All plants that readily throw up root-suckers, 

 as the Hawthorn, Poplar, Elm, Plum, &c, may 

 easily be propagated by cuttings of the roots. 

 Although the normal formation of growth-buds 

 is in the axils of the leaves, yet buds frequently 

 appear irregularly on any part of the stem and 

 also on the roots. These are termed adventitious 

 buds. If healthy, vigorous roots of, for instance, 

 the common Hawthorn, are chopped into short 

 pieces, scattered on the surface of a piece of 

 raked, dug ground, and then covered with soil, 

 they will develop into plants. Although cut- 

 tings of the roots will strike when laid hori- 

 zontally, yet it is better to plant them in an 

 upright position, with their tops level with the 

 surface, or only covered with the slightest pos- 

 sible quantity of soil. The cuttings may be 

 from 3 to 9 inches in length; and in planting, 

 care should be taken that the end which was 

 nearest the stem be placed uppermost. 



The White-thorn, Plum, Apple, Pear, Quince, 

 Eose, Eobinia, Poplar, Elm, Mulberry, Madura, 

 Ehus, Calycanthus, Paulownia, and Sophora are 

 some amongst the many trees which may be 



propagated by roots. Many herbaceous plants, 

 as the Horse-radish, Sea-kale, Anemone japonica, 

 &c, may also be increased in the same way. 

 Some Coniferous plants are difficult to strike 

 from branches, or if they do, are apt to retain 

 the character of branches ; but by root-cuttings, 

 shoots that have the true character of stems are 

 produced. It may be mentioned that a plant 

 raised from a root-cutting bears leaves, flowers, 

 and fruit exactly similar to those of the original 

 tree. For instance, trees have been reared from 

 the roots of the Eibston Pippin, and they pos- 

 sessed all the excellent qualities of that well- 

 known Apple. Many Ferns produce adventitious 

 buds on their roots. Platyceriums may be pro- 

 pagated by means of roots cut off and sown in 

 pans of peat and chopped sphagnum. A series 

 of papers by Mr. Jenman on the ferns which 

 bear root-buds was published in the Gardeners' 

 Chronicle in 1885, vol. xxiv., p. 371, et seq. 



X. — Propagation by Grafting. 



Grafting is an operation in which two cut sur- 

 faces of the same plant, or of different plants, are 

 placed so as to unite and grow together. The 

 cutting, or portion cut off, is termed the scion or 

 graft, and the rooted plant on which it is placed 

 or worked is called the stock. 



The art of grafting is of great antiquity, but 

 by whom it was discovered is not known. It is 

 spoken of by Theophrastus, Aristotle, Varro, 

 Pliny the naturalist, Virgil, Agricola, and other 

 ancient authors. It would appear, however, from 

 their writings that the principles were very im- 

 perfectly understood, otherwise they would not 

 have entertained the belief that the Vine could 

 be grafted on the Walnut or Cherry, and the 

 Peach on the Willow; or that black Eoses would 

 be the result of grafting on the Black Currant; 

 for these plants, having no natural affinity, can 

 never form a vital union, however nc^urately 

 they may be mechanically joined. 



The modes of grafting are exceedingly numer- 

 ous, but they all depend upon one principle, 

 which should be well understood. 



If a tree is cut horizontally through in autumn, 

 or before the sap rises in spring, and if the section 

 be covered over with grafting-clay or other ma- 

 terial, so as to protect it from the drying effects 

 of the air, it will be found that in the course of 

 the season a protrusion of tissue will take place, 

 all round, from between the wood and inner 

 bark. Sap may exude from the woody part of 

 the section, but that sap produces no organized 



