VI PREFACE. 



the Physiology of Plants, free from the trammels of learned descriptions of appa- 

 ratus which of course could not be dispensed with in a text-book or hand-book 

 for specialists. 



Perhaps no other branch of Natural Science is so unknown to the educated 

 public as the Physiology of Plants ; because, in spite of the important progress 

 which has been made in it during the last twenty years, and in spite of the uses to 

 which it may be applied, no one has undertaken to publish its established results 

 in a convenient and intelligible form. This really serious want in our literature 

 I wish to supply by means of my ' Lectures,' and this is of course only possible by 

 the contents being strictly scientific ; only the form of the exposition is to differ from 

 that hitherto customary, in running in phrases which are universally intelligible. 

 The object indicated, ho\\ever, requires also that much which is apparently self- 

 evident to the specialist must here be expressly brought forward and explained, so 

 that a certain prolixity of description is often unavoidable, while, on the other 

 hand, some questions of the day important to the Botanist are entirely passed 

 over or can only be briefly touched upon. Again, having regard to the super- 

 abundance of material, a suitable selection must be made, for, as is well known, 

 the secret of being tedious lies in trying to say all one knows. 



The notes on the literature attached to the separate lectures are only intended 

 for those readers who may be by any chance stimulated by my book to wish for 

 further direction along the untrodden grounds of our literature. 



The publishers were of opinion that a new edition of the systematic part of 

 my ' Text-book ' might conveniently be attached to my ' Lectures.' Since I have 

 myself neither the time nor the inclination to undertake such a new working-up 

 of this domain of Botany, I have made arrangements with Professor Goebel, and 

 he is to compile the systematic portion of my Text-book independently, and 

 according to his own judgment, and publish it as a separate Book, which the 

 reader may employ as a supplement to my ' Lectures.' 



Dr. J. v. SACHS. 



Würzburg, /?/w^ 27///, 18S2. 



