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LETTERS 0]S TREES. 



years, — in short, that the axis is destitute of vitality ; 

 and that in as far as it contributes to the growth and 

 vigour " of the buds and plants, it does so precisely in 

 the same way that the soil does to the vigour and 

 growth of the seedHng plant. And I would fain hope 

 that the evidence already adduced in support of that 

 allegation is sufficient and conclusive. 



17. In his work On Parthenogenesis, published some 

 years ago (in 1849), Professor Owen has enunciated 

 a theory as to the constitution of certain of the lowest 

 tribes of animals, which accords in many, if not in 

 most, of its essential features with that here unfolded 

 as to the constitution of trees. And in vindication of 

 his views, he has adduced like facts to those on which 

 mine as to trees are based, — referring, moreover, to the 

 vegetable kingdom generally, and to trees in particular, 

 as being fashioned on the principle of his theory. 



18. To quote at large from this distinguished author, 

 as I have done from Mirbel and Gaudichaud, would 

 occupy too great a space, and be besides to travel over 

 again, unnecessarily, much the same ground we have 

 already trodden. In another Letter I shall have occa- 

 sion to refer to his views. Meanwhile, I may observe, 

 that reading his work on Parthenogenesis " shortly 

 after its publication, and being struck with the simi- 

 larity of many of his views to mine, I sent Professor 

 Owen a copy of the essay on The Nature, Longevity, 

 and Size of Trees," which I had published two years 



