MICROBE AND LIFE 



in making the various chemical systems found on earth serve their 

 existence and multiplication. Yet all of this is dominated by the re- 

 cognition of the fundamental unity so unmistakably displayed by the 

 diversity of living forms; a unity that cannot otherwise be appre- 

 hended than on the basis of a common origin. 



Thus the microbiologist is destined to acknowledge the potentiali- 

 ties that enabled life to flourish during an early phase of the earth's 

 history, when there was as yet no question of green plant metabolism, 

 based on radiant energy, nor of present-day animal metabolism 

 which, after all, depends on oxygen produced by the plants. Hence, 

 in the mind of the microbiologist there can hardly be room for doubt 

 as to the validity of the thesis that, in its most primitive manifesta- 

 tions, life must have been anaerobic; and he will also be inclined to- 

 wards the conclusion that it must have passed through a pre-cellular 

 stage. This idea finally culminates in H. J. Muller's recent phrase 

 that, seen from a cosmological viewpoint, 'the totality of life is merely 

 a fancy kind of rust afflicting the surfaces of certain lukewarm minor 

 planets'. 



To many among my audience this discourse will have been a sore 

 trial, especially because- my analysis seems to encroach upon the 

 reverence with which man naturally tends to view the mystery of life. 

 Let me therefore emphatically state that the microbiologist, too, is fully 

 cognizant of this mystery which, at certain times, is irresistibly forced 

 upon him, for example when, bent over his microscope, he watches 

 the playful movements of his single-celled objects. And he, no less than 

 any other person, is receptive to the impressions of beauty and har- 

 mony that a contemplation of the infinite variety of the more highly 

 organized living beings is apt to evoke. 



But the desire to establish a closer acquaintance with the multi- 

 farious forms, and to reach a more profound comprehension of the 

 phenomena of life, these are far from being desecrations. In this con- 

 text I may refer to the thorough essay that our fellow-member, Dijk- 

 sterhuis, recently devoted to the subject, 'Mathematics, natural sci- 

 ence, and technology as cultural elements', and particularly to his 

 remark that, from a Christian standpoint, nature is a revelation of 

 God, and hence the study of nature a Christian's duty. 



If, therefore, I have not immediately rejected the idea that some 

 day we may come to conclude that there is continuity from living to 



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