Principles of Gardening ■physiologically considered. 261 



the individual with all its imperfections, metamorphoses, and pe- 

 culiarities, it follows that by this means only can we procure 

 so great a variety of our favourite ornamental plants. There 

 are besides many annuals which rarely bear seed, and can by 

 propagation of the bud be preserved to our gardens : such, 

 reared in the autumn, can be stripped of their young shoots in 

 winter ; and, by continuing this practice, the most valuable can 

 be in no danger of being annihilated. The beautiful TropseY>- 

 lum M.ovitzia?ium may be reckoned among those that have been 

 preserved in this manner. 



The most usual method of propagating in this manner is by 

 a shoot on which are several buds, which is called propagation 

 by division ; and other methods are by single buds detached 

 from the stem in various ways, or even by leaves on which ad- 

 ventitious buds have been formed. The parts to be propagated 

 are divided into two ; viz. those which, when put in the earth, 

 produce roots, and those which are left somewhat out of the soil, 

 and which produce shoots by the developement of buds. 



a. Propagation by Cuttings and. Layers. 



Success in this manner of propagating depends upon many 

 circumstances, all of which must be attended to if you expect 

 favourable results to follow. Attention must be paid, in the first 

 place, to the soil to see that it contains a proportionate mixture, 

 the state of the air, and the necessary degree of heat and moist- 

 ure in both these elements, the time of year in which the cut- 

 tings are made, the cut itself, and the nature of the cuttings. 

 We will make it our study to unfold as clearly as possible the 

 general established principles, and will illustrate them as much 

 as possible by examples, and by reference to physiological rules ; 

 at the same time we must confess, that, however great our exer- 

 tions may be to render the whole as clear as we can, a practice 

 of several years' duration is necessary for a successful application 

 of these principles. It is well known to those who have had 

 much practice in propagating, that, with cuttings which are 

 difficult to strike, the smallest deviation from the established 

 principles is sufficient to produce an unsuccessful result of the 

 operation, while, on the contrary, an opposite practice had al- 

 ways been attended with success. A sufficient acquaintance with 

 all the variations of the locality, and also a careful trial of all 

 the necessary directions proposed, are the chief requisites for a 

 successful result in propagation. 



Cuttings evince a very striking difference with respect to their 

 power of making roots. Some of them, for instance, put out 

 roots with the utmost ease, under all circumstances; others, again, 

 under certain conditions; while others produce them with diffi- 

 culty, under very limited conditions. In general it may be 



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