viii AUTHOR'S PREFACE TO THE SECOND EDITION 



necessary to undertake a large number of the most various 

 physiological experiments and microscopical observations, in 

 order as far as possible to arrive at an independent judgment 

 as to the value and practicability of the methods. Throughout 

 the book special stress has been laid on the establishment of the 

 relations between the anatomical structure and the physiological 

 function of plant organs, and at the same time biological rela- 

 tionships have not been left out of consideration. 



I have taken pains to make the apparatus suggested for the 

 experiments as simple as possible, so that it can be put together 

 by any one without great difficulty. At the same time, of course, 

 certain complicated, and hence also expensive, instruments are 

 indispensable, as, for example, a good microscope, a chemical 

 balance, a spectroscope, an induction coil, a clinostat, etc. 



W. DETMER. 

 JENA, the end of September, 1887. 



AUTHOR'S PREFACE TO THE SECOND 

 EDITION 



IN presenting this Second Edition of my Practical Plant Physi- 

 ology, I am more conscious than ever of the difficulties associated 

 with the preparation of an introduction to physiological experi- 

 ments. These difficulties are partly inherent, and partly due to 

 the fact that the requirements of a course of practical work are 

 by no means the same from all points of view. 



The arrangement of the material is essentially the same as 

 in the First Edition. In other respects, however, the book is 

 essentially a new one, since almost every section has been en- 

 larged or remodelled. I have included many new experiments 

 for lecture demonstration or private work, and have taken pains 

 to render the book increasingly useful to those who propose to 

 make a serious study of plant physiology, and desire especially 

 to familiarise themselves with the methods of research. Hence 

 the efficiency of methods, in this Edition for the same reason often 



