PROPAGATION BY LAYERS. 



355 



buds, and placing the cuttings thus formed 

 slightly under the soil, but not so deep as to 

 cover the top of the bud ; granulation will take 

 place round the edges of the bark, and roots 

 will emit themselves freely. When these have 

 become sufficiently formed, they must be taken 

 up and planted in a prepared bed, to gain suffi- 

 cient strength for planting out permanently. 

 By this process, from fifty to a hundred plants 

 may be produced from one. Holyhocks raised 

 from seed, however carefully saved, can never 

 be depended upon for perpetuating the iden- 

 tical variety. 



The importance of buds in the propagation of 

 plants, although well known to botanists, has 

 hitherto been comparatively little attended to 

 by propagators in general. Their universality is 

 much greater than is usually thought ; for as 

 has been stated by Professor Balfour, in " Class 

 Book of Botany," the higher classes of plants 

 may be considered as consisting of numerous 

 buds united on a common axis. These possess 

 a certain amount of independent vitality, and 

 they may be separated from the parent stem in 

 such a way as to give origin to new individuals. 

 In some instances buds are produced, which 



are detached spontaneously at a certain period 

 of a plant's life, as instanced in stem buds of 

 Lilium bulbiferum, L. tigrinum, lxia bulbifera, 

 &c. " The cloves formed in the axles of the 

 scales of bulbs are gemmae, or buds which can 

 be detached so as to form new plants. Such is 

 also the case with the corms of Colchicum. In 

 these instances buds are developed in the usual 

 way in the axles of leaves or scales — that is to 

 say, at the points where they join the stem." 

 Besides the true or visible buds, there are 

 embryo buds contained in the bark of many, 

 nay, probably of most trees. Of these are the 

 excrescences called uovoli, found in the bark of 

 old olive-trees, and, according to Signor Manetti, 

 used by the Italian gardeners for propagating 

 that tree. These are supposed by Professor 

 Lindley to have been " adventitious buds deve- 

 loped in the bark, and by the pressure of the 

 surrounding parts forced into those tortuous 

 woody masses in the shape of which we find 

 them." It does not appear that advantage has 

 hitherto been taken in this country of these as 

 a means of increasing the trees on which they 

 are found, although there is little doubt they 

 might be employed in cases of emergency. 



