73 On. the Reproduction of Buds i 



their component parts from the bark or not, I shall not ven- 

 ture to decide ; but I am much disposed to behove that, hke 

 those of the potatoe, they sprang from the alburnous sub- 

 stance solely. 



The space, however, in the annua! root, between the 

 medulla and the bark is very small ; and therefore it may 

 be contended that the buds in these instances may have 

 oricfinated from the medulla. I therefore thouffht it neces- 

 sary to repeat similar experiments on the roots and trunks 

 of old trees, and by these the buds were reproduced precisely 

 in the same manner as the annual roots : and therefore, 

 conccivino; myself to have proved in a former memoir* 

 that the substance which has been called the medullary pro- 

 cess does not originate from the medulla, I must conclude 

 that reproduced buds do not spring from that substance. 



I have remarked in a paper which you did me the honour 

 to lay before the Royal Society in the commencement of the 

 present year, that the alburnous tubes at their termination 

 upwards invariably join the central vessels, and that these 

 vessels, which appear to derive their origin from the albur- 

 nous tubes, convey nutriment, and probably give existence 

 to new buds and leaves. It is also f^vidcnt, from the facility 

 with which the rising sap is transferred from one side of a 

 bounded tree to the other, that the alburnous tubes possess 

 lateral, as well as terminal, orifices : and it does not appear 

 improbable, that the lateral as well as the terminal orifices of 

 the alburnous tubes may possess the power to generate cen-^ 

 tral vessels j which vessels evidently feed, if they do not 

 give existence to, the reproduced buds and leaves. And 

 therefore, as the preceding experiments appear to prove that 

 the buds neither spring from the medulla nor the bark, I am 

 much inclined to believe that they are generated by centraE 

 vaBsels which spring from the lateral orifices of the albur- 

 nous tubes. The practicability of propagating some plants 

 from their leaves may seem to stand in opposition to this 

 hypothesis ; but the central vessel is always a component 

 part of the loaf, and from it the bud and young plant pro- 

 bablv originate, 



* Phil. Trans, of 1803, 



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