204 PHYSIOLOGICAL BOTANY. 



the stem, and then traverse it in its entire length. Near 

 the periphery the vascular bundles are so crowded that it 

 is difficult to separate them and ascertain their course. 



Gaudichaud continues : " We shall naturally apply this 

 principle to the growth of the stem, leaves, fruit, &c., and 

 also extend it to the flowers and other deciduous parts of 

 plants. We would also apply it to the stem of Vellosia, 

 which, as it derives scarcely anything from the leaves 

 which exist at the ends of the branches, always remains 

 very thin, for the simple reason that the vessels of the roots 

 of the leaves which should produce the increased thickness 

 of the stem, become applied immediately after their for- 

 mation to the external part of the bark (a Vexterieur du 

 perixyle), and thus descend as roots (a Tetat de ratines), 

 along the twigs, the branches, and leaves, to the ground. 

 The primordial leaf (that first formed after the embryo), 

 undoubtedly obtains life and nutriment, but nothing fur- 

 ther, from the embryo; the primordial leaf also imparts 

 vitality and its principal nutriment to the second leaf, and 

 the same occurs with the second leaf in regard to the 

 third, &c." 



Gaudichaud always writes in this aphoristic style, 

 which becomes more remarkable from his separating the 

 sentences from each other, and commencing a new line. 



Again, he says (1. c. p. 610): " In fact, since it is found 

 by observation, that the embryo, this small isolated being, 

 consists originally of cellular tissue only, and that this 

 cellular tissue produces the vessels by its physiological 

 action ; that the vessels commence in the internodes of 

 the stern (merithale tigillaire), then appear in the petiolary 

 and the laminary merithals of the leaf; that they are per- 

 fectly formed, or at least may be traced in these regions 

 (dans les parties merithattiennes), before they appear in the 

 papilla of the rootlet (mammelon radiculaire), we are led 

 by analogy to consider that the same must also be the case 

 with the organization of other individuals, of whatever 

 kind they may be, which are produced by plants. This 

 fact I repeat is an important one, and worthy of conside- 



