TO THE MEMORY OF 



CHRISTIAN KONRAD SPRENGEL 



FORMERLY RECTOR OF THE GREAT LUTHERAN TOWN-SCHOOL IN SPANDAU 



BORN AT BRANDENBURG ON THE HAVEL IN I75O 



DIED AT BERLIN ON APRIL 7TH, 1816 



AND 



DR. HERMANN MULLER 



FORMERLY PROFESSOR IN THE REALSCHULE AT LIPPSTADT IN WESTPHALIA 



BORN AT MUHLBERG IN THURINGIA ON SEPTEMBER 23RD, 1829 



DIED AT PRAD IN THE TYROL ON AUGUST 25TH, 1883 



Christian Konrad Sprengel and Hermann Muller were characterized 

 by untiring diligence and ardour for research, incomparable powers of obser- 

 vation, and extraordinary acuteness in the interpretation of the phenomena 

 of Flower Pollination. With this was united in a conspicuous degree the 

 ability to describe their discoveries in a most admirable manner. Their 

 fundamentally important works on Flower Pollination are now, therefore, 

 an inexhaustible source of instruction and enjoyment, as they must always be. 

 This book, which shows the present position of the Science of Flower 

 Pollination, is dedicated to the memory of these two great investigators. 



