224 TRANSLATIONS AND SELECTED ARTICLES. 



But, however numerous, the researches of this kind made up to the 

 present time still amount to very little, if we compare them with the 

 immensity of the field which remains to he explored ; and yet they 

 already tend to shew an evident and remarkable relation between 

 anatomical structure and classification. 



[The author then enters upon the peculiarities of internal struc- 

 ture belonging to the Gymnosperms, and points out the error of those 

 who have supposed the same peculiarities to occur in any other tribes. 

 He goes on to sketch the history of anatomical research in relation 

 to the particular families, concluding with a reference to the important 

 work, still in progress, of M. Chatin. We conclude our extract with a 

 few paragraphs through which M. Regnault approaches his own 

 special investigations, upon the particulars of which it is out of our 

 power now to enter.] 



The structure of stems may vary much, not only according to the 

 position of the plant in a natural classification, but also according to 

 the conditions of vegetation in which it lives, the medium in which it 

 grows, &c. Those stems which unite with a ligneous substance the 

 property of climbing, have in general a structure modified in refer- 

 ence to this particular function ; and if some families, as that of 

 Lardisabalaceee, long since studied by M. Decaisne {Archives du 

 Museum d' Kistoire Naturelle, 1839) are made up entirely of climbers, 

 there are many others, such as Bignoniacese, Sapindacese, Malpighi- 

 acese, Convolvulacese, which, whilst they have woody climbing genera, 

 contain also plants capable of supporting themselves independently. 

 Long since, Adrien de Jussieu drew attention to the fact {Diet. 

 d%istoire Naturelle, xii. 432), that in these variously constructed 

 plants belonging to the same family, the essential anatomical charac- 

 ters remain unchanged, equally in the climbing species and the others ; 

 only in the former they unite themselves with other characters com- 

 mon to all climbers, and a practical eye will always recognise to which 

 of the above-named families a section of a trunk belongs which is 

 brought under his notice. Comparative anatomy must here, then, 

 according to A. de Jussieu, have a double value, being able at the 

 same time to make us acquainted with the natural group to which the 

 plant belongs, and to indicate to a certain extent the mode of growth 

 of the species. Numerous observations are evidently necessary be- 

 fore the facts of vegetable anatomy are sufficiently known for us to 

 be able to give them so precise a signification. It is even probable 



