CHAPTER VII 



BEIJERINCK AT WORK 



Before proceeding to an account of the last period of BEIJERINCK'S 

 life, it seems fitting to give here a brief analysis of BEIJERINCK'S 

 methods of working. It is not intended to enter into details regarding 

 BEIJERINCK'S approach to the numerous problems which occupied his 

 attention. Such matters will be adequately dealt with in Parts II and 

 III of this book. However, it is felt that a description of BEIJERINCK'S 

 general laboratory technique, and a consideration of the factors which 

 determined the choice of the subjects of his investigations may not be 

 omitted here. 



Above all, it should be stressed that BEIJERINCK was an ex- 

 ceptionally keen observer. The starting point is for most of his in- 

 vestigations, especially in the first phase of his scientific activity, to 

 be found in observations made either in nature, or during laboratory 

 experiments. His classical studies on galls and gall insects are char- 

 acteristic of his rare gifts for observing plant and insect life, and for 

 giving an interpretation of the phenomena observed. 



However, BEIJERINCK was also a man of great learning and wide 

 reading, and, during his later years especially, it was often something 

 he had read in scientific literature that stimulated him to undertake 

 investigations which frequently led to new and unexpected results. 



BEIJERINCK'S ability to fuse the results of remarkable observations 

 with a profound and extensive knowledge of biology and the under- 

 lying sciences has undoubtedly been responsible for the great success 

 of his work. 



Characteristic of BEIJERINCK'S mode of attack of the various 

 problems is the fact that he generally started with a quite definite 

 "working hypothesis" which was then submitted to \vell chosen 

 experimental tests. Depending on the results obtained the hypothesis 

 was amended, and then, once more, critically tested. In these experi- 

 ments BEIJERINCK profited by his ever increasing experience, and 

 unlike more specialized investigators - - he was able to mobilize his 

 great empirical knowledge of the fields of physiology, experimental 

 morphology, chemistry and physics. However, the applications he 



] ) In the drawing-up of this chapter the author has freely used, and has greatly 

 profited from an expose by Prof. VAN ITERSON, who during many years, in which 

 BEIJERINCK'S scientific activity culminated, was in daily contact with the great 

 scientist. He also wishes to gratefully acknowledge spveral contributions made by Mr. 

 H. C. JACOBSEN, for whom the same holds. 



