SELECTED PAPERS 



tween the properties of living and those of inanimate matter! If, driven 

 by the recognition of the mystery of life, the layman then takes cog- 

 nizance of the results obtained by the investigators who aim at ac- 

 quiring a comprehension of vital phenomena, one may reasonably 

 anticipate that marvel will be added to admiration. For the number 

 of manifestations of life on earth appears to be immense ; the natural 

 cycle of development traversed by all these living entities represents 

 a well-nigh endless diversity. And whosoever rises above this impress- 

 ive descriptive science to the hights of experimental biology, and con- 

 siders, for example, the results of recent studies on the phenomena of 

 regeneration, cannot fail to 'become deeply imbued with the im- 

 penetrable mystery of life, of the divine urge towards harmony that 

 governs all living nature', as has been stated by Boeke. Truly, with 

 such vistas before him, the biologist must be allowed his modicum of 

 superiority; it is a proud feeling to be permitted to engage in the 

 service that is the study of life. 



Now the microbiologist, by which I mean only the scientist who 

 studies the micro-organisms for their own sake rather than the in- 

 vestigator who has earned his epithet as biologist by the fact that 

 he tries to protect the higher organisms, whether plants or animals, 

 from microbial invasion, occupies a somewhat exceptional place 

 among biologists on account of the peculiarities of the organisms he 

 studies. Nevertheless, above all else he is apt to feel united with other 

 biologists because he is imbued with the validity of Rubner's dictum : 

 'Was lebt, - ist Eins, daher muss trotz der Varianten, welche die ein- 

 zelnen Spezies vorstellen, in ihrem Leben das gemeinsame Bild des 

 Ganzen sich widerspiegeln'. How strikingly has not the truth of this 

 passage been demonstrated, particularly during the past few decennia. 

 Does one not, time and again, observe that the investigators of higher 

 forms of life deign to descend to studies with one-celled organisms such 

 as bacteria, yeasts, algae, etc., in order there to seek and frequently 

 also to find the answers to their problems? 



But this does not alter the fact that in many instances the mystery 

 of life will force itself upon the microbiologist less directly. How often 

 does he not sit bent over his microscope, torturing himself with the 

 question whether some corpuscle in his field of vision may or may not 

 lay claim to the glorious predicate 'living'? How simple, and in a 

 sense transparent are not many of the chemical transformations per- 



330 



