Preface vii 



line. This is done because having an illustrated textbook in the 

 students' hands renders certain changes in the outline advisable. 

 These changes are now being made and the outline will be pub- 

 lished in the near future. In it a fuller explanation of how the 

 laboratory and field work has been conducted will be given. 



Throughout the book the author has tried to avoid purposeful 

 explanations and words implying such explanations. Teleology 

 answers all questions by the easiest method, and closes the mind 

 of the student to the means by which scientific explanations may 

 be discovered. It is an inheritance from the dark ages and 

 should be eradicated from the laboratory and classroom. Stu- 

 dents should learn at the very beginning that plant phenomena, 

 so far as we now know, take place in the plant in accord with the 

 laws of physics and chemistry ; that they do not happen because 

 of some alleged purpose any more than hydrochloric acid unites 

 with soda in order to form table salt. If certain phenomena 

 and structures eventuate to the advantage of the plant, well and 

 good. There are many that do not ! And neither the advanta- 

 geous nor the disadvantageous should be cited as a cause. 



E. N. T. 



