OF PLANTS. 97 



which originates first, and, therefore, is the oldest part 

 of the organ ; it grows only at the. base, where it is con- 

 nected with the stem, and this only for a certain length 

 of time, being thus, as it were, pushed up out of the 

 stem. This is a leaf in the widest signification of the 

 term. While the former exhibited unlimited growth, 

 the latter is through trie very mode of its formation 

 arrested at a certain boundary. We perceive two things 

 here: first, that the stem and the leaf are actually 

 contrasted with one another ; only where the one is present 

 can we speak of the other. From this we draw a distinc- 

 tion in the plants of this primary division, and separate 

 the stemless plants from those with stems. Secondly, 

 it follows, from what has been premised, that the plant 

 in general can have but two essentially different organs, 

 namely, leaf and stem, and that all the remaining so-called 

 organs of the plant must be only unimportant variations 

 of form of one of these organs, or, structures resulting 

 from the combination and blending together of both. 

 This proposition was first definitely expressed by Caspar 

 Frederic Wolff and Gothe, and the result of the obser- 

 vation, that all the organs of a plant possessing a stem 

 may be traced back to one or other of the elementary 

 organs, has given rise to a peculiar study, which is univer- 

 sally known by the name given to it by Gothe, " the 

 metamorphosis of plants." What has already been revealed 

 by publications now in our possession, includes but a very 

 small part of that branch of study, which, as Morphology, 

 will hereafter be the most essential section of all Botany. 



We might here easily give a brief review of this subject, 

 by an example, without entering into all the individual 

 points which still contain many difficulties and unsolved 

 problems. The most important, however, have already 



7 



