PREFACE 



It is now forty years since De Bary's classic Comparative 

 Anatomy of the Vegetative Organs of the Phanerogams and Ferns 

 made its appearance. In the interval much has been added to 

 our knowledge, particularly in the paleobotanical and experimental 

 fields. The doctrine of descent, too, has now reached a degree of 

 prominence and importance which it did not possess in De Bary's 

 time. As a consequence, it is desirable that the general subject 

 of the anatomy of the woody or so-called vascular plants should 

 be reviewed, with special reference to its historical and experi- 

 mental aspects. This is perhaps all the more desirable as an 

 effective counterpoise to the extreme mechanistic tendencies of 

 the time. It will accordingly serve a useful purpose to indicate 

 how large a part of the organization of existing plants is an inherit- 

 ance from their ancestors of earlier geological times. 



In De Bary's textbook both paleobotany and development 

 are deliberately eschewed. The first of these is now essential for 

 any adequate comprehension of comparative anatomy in its 

 all-important evolutionary aspects. It is abundantly clear that 

 the most fruitful results from the standpoint of the doctrine of 

 descent are to be derived from the comparative study of extinct 

 and existing plants belonging to the same orders, families, or 

 genera. It is, moreover, obvious that the living forms cannot 

 be interpreted without a knowledge of their past, and that to 

 an even greater degree the organization of fossil plants is a closed 

 book to those who are unfamiliar with the anatomy of allied and 

 still living types. The wide range of facts which must of necessity 

 be covered calls for a somewhat brief and even elementary treat- 

 ment. Fortunately, since De Bary's time, it has become more 

 and more evident that the study of the development of organs 

 and tissues throws little trustworthy light on the processes of 

 evolution, and consequently that aspect of our subject need 

 receive no more attention than was vouchsafed to it by the great 

 German anatomist nearly half a century ago. 



