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SECTION II. 



REMARKS ON THE DISTINCTIVE CHARACTERS OF THE DIFFERENT TRIBES 

 OF PLANTS IN GENERAL, AND OF THE CONIFERS IN PARTICULAR. 



Although the organization of vegetables is sufficiently known, in so 

 far as regards the distinctions by which the larger groups are defined, the 

 more peculiar features which the families and genera present, have not yet 

 received that degree of attention which they require. The less perceptible 

 modifications of structure exhibited by species of the same genus are neces- 

 sarily still less known ; and, indeed, when we find that the anatomist is 

 unable to define the species of animals by characters derived from their in- 

 ternal structure, we need not wonder that the botanist should fail in distin- 

 guishing those of the vegetable kingdom by similar indications. When I 

 commenced my inquiries into the structure of fossil plants, I was not aware 

 that even the families of recent vegetables had received anatomical investi- 

 gation, in such a degree at least as to afford any essential aid to the geolo- 

 gist. The assistance which I then received, I acknowledged in the work 

 published by me in 1831 ; but I have since found that the peculiar charac- 

 ters of the different kinds of woody stems have been more minutely given 

 by Dr Kieser, in his Memoire sur reorganisation des Plantes, of the in- 

 formation conveyed by which I have therefore availed myself. Labouring 

 under these disadvantages, it will readily be understood how difficult a task 

 it was to me to arrive at any satisfactory results in my investigation of fossil 

 vegetables. I had before me an unknown region, in which I could per- 

 ceive no footsteps of any previous adventurer ; but I hoped at least to open 

 up a path which others might extend. Nor, although I may have erred 

 in confining my investigation to the structure as exhibited by transverse 

 sections alone, have my labours been without benefit. In their Fossil Flora 



