PREFACE vii 



No attempt has been made to present the anatomy of Seed- 

 plants. This subject is too vast, and too far removed from our 

 general purpose to be included. The few anatomical details 

 which have been given are simply those which have to do with 

 the general structure of organs, and which are essential to any 

 morphological discussion. 



The authors appreciate the fact that, in a certain sense, a 

 book of this nature is out of date as soon as it has left the press, 

 especially as it deals with groups which are being investigated at 

 the present time with remarkable activity. Doubtless, within a 

 few months papers will appear which would have been of great 

 service; but in so large a group this is likely to remain always 

 true, and the authors have felt that a concise summary of knowl- 

 edge at any stage of progress is useful in stimulating and guiding 

 further research. 



John M. Coulter. 



Charles J. Chamberlain. 

 The University of Chicago, 

 Ja/nua/ry, 1901. 



