LIFE S FRINGES 



formed by microbes, so much so that present-day industry sometimes 

 gladly makes use of them. Is it not pardonable if the microbiologist, 

 who, by opening a single valve, daily causes Clostridium acetobutylicum 

 rapidly to convert 50,000 gallons of corn meal mash into a solution 

 rich in butanol and acetone, does not always keenly realize the 

 mystery of life, and unconsciously considers the operation on a par 

 with similar reactions in which, e.g., strong acids are the causal agent? 

 This, indicated summarily, is why the microbiologist occupies an 

 exceptional position, also in our association. Less haughty - probably 

 less humble as well - than the student of higher forms of life, he 

 seems predestined to form a natural link between the latter and the 

 student of the more exact branches of natural science. I shall consider 

 myself fortunate if the following discussion may contribute to an 

 acceptance of this conviction in wider circles. 



As already remarked, the microbiologist is as much imbued with the 

 mysteriousness of life as any one else, during moments of introspection 

 and reflection. This, for example, will happen when he observes with his 

 microscope an actively moving, small bacterial type such as Bacterium 

 prodigiosum, and delights for a while in the merry antics of the barely 

 visible individuals. Here the mystery is again tangible, and inscrutable 

 the sense of so minuscule an expression of life, the fate and destiny 

 of every separate living individual. In these days, when the whale has 

 claimed the attention of our entire nation, the microbiologist inevit- 

 ably must ponder the overwhelming contrast in dimensions of such 

 manifestations of life with those it is his lot to study; a contrast I can 

 best illustrate by pointing out that, had I requested the draughtsman 

 of the figure* to produce, by the side of the excellent likeness of B. pro- 

 digiosum, another one, representing the largest present-day animal, the 

 whale, on the same scale, the figure should have a length corresponding 

 to the earth's radius. Such thoughts lead the microbiologist to the 

 question whether an organism like the above-mentioned bacterial 

 species actually represents life in its smallest dimensions, and invol- 

 untarily he is tempted to drag out his microscope and search for in- 

 creasingly smaller forms of life. And indeed he will book some suc- 

 cesses, for bacteria such as Spirillum parvum and a few others, whose 



* Ed. note: At the lecture figures of the dimensions of bacteria, viruses and large 

 molecules were shown. 



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