PREFACE. 



nnHE Elements of Botany appeared in 1895, and with 

 a few alterations was stereotyped in the following 

 year. I take the present opportunity of correcting one 

 or two obscurities or mistakes. If the book could have 

 been rewritten it might have been advisable to introduce 

 the conception of the stele, which helps to make clear the 

 identity of the central vascular cylinders of the Dicoty- 

 ledonous stem and root a point in .which the older 

 terminology is less effective. For this purpose it is allow- 

 able to define the stele as a group of tissues characterised 

 by the predominance of conducting elements and contained 

 within an endodermis. Used in this sense the word stele 

 also coordinates the vascular anatomy of the Dicotyledon 

 with that of the fern-rhizome, whereas the term vascular 

 bundle, used in these instances, may confuse the beginner. 

 It seems to me that broad resemblances between different 

 types of vascular arrangement are to the elementary 



