216 VEGETABLE ORGANOGRAPHY. 



earth, and the new roots proceed entirely from points 

 where no young branches existed ; as for the old roots 

 elevated into the air, all the small ones die, and adventi- 

 tious buds are developed upon the old trunks. 



We see, then, from all that I have set forth, that 

 althouorh there do exist resemblances between stems and 

 roots, these two essential organs cannot by any means 

 be confounded. Hedwig wished the root alone to be 

 considered as the body of the plant, because in several 

 perennial herbs the stem perishes each year, and the 

 root alone retains the vitality of the individual ; but it 

 is certain, in this example, that the stem does not 

 entirely perish ; and, moreover, in the phenomena of 

 cuttings, it is the reverse which takes place, since the 

 stem develops new roots. The stem and root, then, 

 ought to be considered as of equal importance, their 

 union constituting the body of the plant. A plant, then, 

 is composed of two cones (in Exogens), or of two cylin- 

 ders (in Endogens), applied to each other by their bases, 

 placed vertically, and elongating indefinitely by their 

 extremities. 



Section II. 

 Of the Parts of Roots, and of their various Forms. 



Roots considered in a transverse section present, as 

 we have before said, the same parts as stems, excepting 

 that those of Exogens have no pith. Considered longi- 

 tudinally, they are distinguished, like stems, into the 

 trunk, and principal or secondary branches ; but if these 

 parts, which form as it were the fi'amework of the root. 



