viii editor's note 



undertaken by Miss Aleita Hopping, working in this Laboratory. Out of her 

 translation the present book has developed. 



Aside from its usefulness to university students, Palladin's treatise ought to 

 be of great value to more advanced investigators, especially as it furnishes a 

 summary of a large amount of the literature of the subject, and it is hoped that 

 the present edition may prove helpful to the many EngUsh-speaking workers 

 who are engaged in physiological research as applied to agriculture and forestry.. 

 To specialists in its own field the book may serve as a convenient means of ap- 

 proach to Palladin's general interpretations. Finally, the numerous Russian 

 references may help to open the domain of Russian science to English-speaking 

 students and to emphasize the rapidly growing importance of Russian research 

 in this subject. 



As this translation was nearing completion. Prof. Palladin very kindly 

 furnished the editor with a copy of the seventh Russian edition, with those 

 passages marked in which the latter differs from the sixth Russian edition (from 

 which the German was directly derived), and it seemed desirable to make the 

 present book conform with the author's latest alterations as far as possible. 

 Dr. E. E. Free, also of this Laboratory, has made the necessary translations 

 from the Russian, following Prof. Palladin's notations, and these alterations are 

 included in the English text as here brought forth. 



The body of the text aims to be primarily a trye translation of the German 

 edition, and the original forms of expression have been retained in practically 

 all cases where this was at all possible in English. The general attitude of the 

 author is so obviously opposed to teleological reasoning that the non-teleological 

 point of view has been made unmistakable in those few places where the German 

 text might leave the reader uncertain in this regard. Palladin's writing is more 

 free from teleological misinterpretations of the relations between conditions and 

 results than is that in most of the text-books hitherto available, and this fact 

 was one of the reasons for the undertaking of the present translation. It will 

 doubtless be a long time before teleology may be deleted from physiological 

 writing and thinking, but readers with a teleological point of view, who may still 

 be satisfied with the consideration of results or effects, in place of conditions or 

 causes that may be as yet unknown, wiU perhaps not object seriously to an em- 

 phasis upon the conviction that permanent progress does not lie in this direction. 

 Few other alterations have been made, these consisting mainly in some modifica- 

 tions in the order of presentation, some slight additions that render certain 

 statements more easily understood, and a very few changes in terminology that 

 seemed desirable. Slight additions are sometimes indicated by being enclosed 

 in brackets. 



Editorial notes have been added here and there, in the form of footnotes, 

 which are uniformly signed "Ed." Footnotes not thus designated are Palladin's 

 own. The editorial notes give such additional matter as has seemed desirable, 

 either for completeness of presentation or for a better understanding by English- 

 speaking readers. They constitute, in the aggregate, only a small portion of 

 the volume. 



