TRANSLATOR'S PREFACE. 



WHILE studying in the laboratory of Dr. Far- 

 low, at Harvard University, in 1881, I first be- 

 came acquainted with the German translation of 

 Poulsen's little treatise, which made its appear- 

 ance in this country about that time. It was 

 proved so valuable by every-day use in the labora- 

 tory, both there and with my classes in the Uni- 

 versity of Wisconsin, that I began a translation of 

 the most frequently used parts, having in mind at 

 first only the convenience of my own students. 

 But several requests having been made that I 

 should complete the translation and publish it, I 

 decided to do so, having received an offer of addi- 

 tional notes from the author. Various causes, how- 

 ever, have delayed my work, so that it is but now, 

 above a year since it was begun, that it is completed. 



It should be said that the translation is in no 

 sense a literal one. The obvious meaning of the 

 author has been given, but with no effort to pre- 

 serve the idiom or vocabulary, and the usual Eng- 

 lish terminology has commonly been employed. 



In presenting my translation to American teach- 

 ers of vegetable histology, I feel confident that it 

 will meet the every-day wants of the laboratory. 



WM. TRELEASE. 



MADISON, Wis., April 12, 1883. 



