APOLOGY 



eluding, contemplating part 'Kluyver as seen by his pupils' by Dr. 

 W. J. M. la Riviere, since 1952 a co-worker of the laboratory, to 

 be a happy addition to the knowledge of Kluyver's personality, 

 especially because of its comprising qualities. 



We express our appreciation to Prof. Dr. O. Bottema, Rector Mag- 

 nificus of the Technological University, for granting premission to 

 include the funeral oration he delivered at Westerveld, and to Prof. 

 Dr. A. van Rossem for the version of his speech on that occasion. 



It appeared desirable to confine the republication of Kluyver's oeuvre 

 as much as possible to papers of which he was the sole author. There- 

 fore only two articles have been included that were written in collab- 

 oration with associates [1926; 1936]. Though it would have been 

 attractive to reprint also Kluyver's Doctor's dissertation, we were 

 dissuaded from doing so, if for no other reason than its very size. 

 Hence the 'Selected Papers' cover exclusively the span of his profes- 

 sorate. We have striven to make a selection such that it fairly covers 

 this entire period. 



Along with the inaugural address [1922], the lecture that represents 

 a first reconnaissance [1924], and the publication [1926] that con- 

 tains an outline of the impressive research program constitute a 

 logical introduction. The 1931 and 1936 papers portray the search for 

 an approach that would permit the fundamental unity in the diversity 

 of microorganisms to find expression also in the field of systematics. 

 The Helsinki lecture [1939] reveals Kluyver's early interest in carbon 

 dioxide assimilation by microbes devoid of chlorophyll. The talent 

 for expounding both a broad and a narrow subject, such as the evo- 

 lution of microbiological science or a particular problem of more 

 transitory significance, is clearly evident from the 1947 and 1952 

 papers. 



For readers not trained in microbiology the inclusion of the 1937, 

 1949, and 1955 lectures, in English translations, affords an opportunity 

 to acquaint themselves with Kluyver's approaches and concepts. At the 

 same time these papers amply evince Kluyver's wide range of interests. 



The scientific publication of 1953 shows Kluyver's undiminished 

 interest in the problems concerned with hydrogen transfer. The other 

 contribution of the same year divulges something of his ideas on the 

 relationship between the scientist and his social environment. 



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