LECT, VII.] ANATOMY OF STEMS* 345 



" burnum of the Apple tree, I did not discover any 

 " traces of the sinuosities I had noticed ; nor was 

 " the uneven surface of the alburnum of the Crab 

 " tree more changed by the smooth transposed 

 " bark of the Apple tree* The newly generated 

 " alburnum, beneath the transposed bark, ap- 

 " peared perfectly similar to that of other parts of 

 " the stock, and the direction of the fibres and 

 " vessels did not in any degree correspond with 

 " those of the transposed bark *." Nothing, in 

 my opinion, can be more decisive of the ques- 

 tion than this experiment ; for, although Mr. 

 Knight himself modestly suggests that it is not 

 " calculated to prove that the newly generated 

 " bark was not converted into alburnum ;" yet it 

 is not probable that the merely transposing the 

 bark of one tree to another would alter the ori- 

 ginal features of the liber of the transferred por- 

 tion in so short a period as one season, if such a 

 change should even afterwards occur ; of which, 

 however, we have no evidence. The obvious con- 

 clusion therefore to be drawn from this experiment 

 is, that although the alburnum is generated 

 through the medium of the bark, yet, it is deci- 

 dedly not transmuted liber. 



The opinion of Mr. Knight is, that the bark 

 deposits the alburnous matter ; but that the leaves 



* Phil. Trans. 1808, Part I. p. 104-5. 

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