250 ON PROPAGATION BY CUTTINGS. 



their leaves, roots are protruded from the lower end of the cutting, just as the 

 radicle is protruded from a seed ; while the moisture absorbed by the cuttings 

 with the leaves on enables the leaves to continue performing their functions 

 and ultimately to send down organisable matter to the lower end of the cut- 

 ting, which sooner or later protrudes from it in the form of roots. In the pro- 

 gress of this process, the organizable matter in many species first appears as 

 a callosity on the lower end of the cutting, sometimes covering only that 

 portion of it from which the roots are protruded, viz., between the bark and 

 the wood, as is often seen in the cuttings of roses and gooseberries, and some- 

 times covering the entire section, as in cuttings of geraniums and fuchsias. 

 Though by theory all leafy-stemmed plants may be propagated by cut- 

 tings, yet in practice this is found very difficult to effect with some species, 

 and with a few that mode of propagation has never yet been accomplished; but 

 this applies to so very few, that the exception hardly merits notice. Indeed 

 such is the rapidly increasing skill in gardeners, that in a very short time 

 there will probably be no exceptions whatever. The German gardeners 

 have lately rooted cuttings in charcoal which could never be rooted before 

 by any means. (See Gard. Mag. for 1841.) 



574. Selecting plants from which the cuttings are to be taken. Every plant 

 from which cuttings are taken ought to be healthy, because in a diseased 

 state the cutting cannot perform the functions necessary to produce roots ; 

 and besides, excepting in the case of variegated plants and a few others, it is 

 not desirable to propagate disease. It is found from experience, that cut- 

 tings taken from the lower branches of plants which are near the soil, root 

 more readily than such as are near the summit of the plant and are sur- 

 rounded by drier air ; doubtless because the tissue of the wood which con- 

 tains the nutriment is in a more concentrated and hardened state in the 

 latter case than in the former. Hence the practice of putting plants which 

 are difficult to strike into a warm moist atmosphere, and keeping them there 

 till they have produced shoots sufficiently soft in texture to ensure their 

 rooting. Hence cuttings of evergreens, such as the holly and laurel, strike 

 more readily after a wet season than after a dry one, and better in the Irish 

 nurseries than in those of England or France. Hence also the practice of 

 nurserymen of forcing plants in pots for a few weeks before cuttings are 

 taken off, in order to get young growing wood, or placing green-house plants 

 in the open air during summer, in order to get succulent wood. The 

 latter practice is sometimes used in the case of heaths, and the former in 

 the case of the finer sorts of China roses, dahlias, and a great many green- 

 house plants. On the same principle is founded the growing of plants 

 from which nurserymen intend to propagate, in pits to which very little 

 fresh air is given, and which are kept perpetually moist, so that all the 

 wood produced, whether by the top or side branches, is equally soft and fit 

 for making cuttings. Perhaps the most successful propagator of house 

 plants by cuttings in Britain is Mr. Cunningham, of the Comely Bank 

 Nursery, Edinburgh, and his success is principally owing to his growing the 

 plants, from which the cuttings are to be taken, in a close, moist, warm 

 atmosphere. Mr. Cunningham's plant- structures have in general no front 

 glass, and indeed for the most part may be considered as pits ; many of 

 them, however, on a very large scale. The closeness, it is obvious, is pro- 

 duced by giving very little air at any time, and none except when the tem- 

 perature is raised to an extraordinary degree by sun heat. The moisture is 



