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LETTERS ON TREES. 



spoken of the bud " as producing stem, and root, 

 and flowers, and fruit, as well as leaves, — in short, all 

 the parts entering into the constitution of the most 

 perfect seedhng-plant. Nor need I remind you that 

 to substantiate this, — to shew that the bud is adequate 

 to the production of every thing that the seed is, forms 

 the burden of a large part of the reasoning in that 

 paper. I then thought, and still think, that I suc- 

 ceeded in doing so ; and therefore see nothing in this 

 objection that is of weight or value against the theory. 

 At the same time, I readily allow that in relation to 

 the production of the concentric woody layers, the 

 leaf is the part of the plant essentially concerned ; and 

 I will, by and by, endeavour to shew, that in regarding 

 it as only the most important of the vegetative organs 

 of the plant, and as having for its sole ofiice that of ela- 

 borating the sap, Dr Carpenter has very inadequately 

 represented the character and relations of the leaf. 



6. The part of the plant, of which in Dr Carpen- 

 ter's estimation too little account is made, is, the gene- 

 ral cellular basis ; and it is here that the full force of 

 the objection is brought out. After stating, that 

 " whilst too much account is made of the leaves as 

 integral components of the plant," Dr Carpenter goes 

 on to say, " too little is made of the general cellular 

 basis, from which the leaves originate, and which 

 retains its vitality in every stem, through the whole 

 period of its existence." And he adds, — 



