CHAPTER I 



The Appearance of Life 



OF all the problems with which man's mind has wrestled the 

 most perplexing is that concerned with the origin of life, 

 embracing as it does the problems of humanity's own origin. 

 Even before science came into being, the most daring thinkers 

 of every age attempted to find some explanation for it, as the 

 forms of life, among which we ourselves occupy the most exalted 

 position, confront us on all sides in a far more insistent manner 

 than even the phenomena of wind and weather. Our ancestors 

 had to move about in enormous forests where they encountered 

 powerful adversaries, against which they had continually to 

 measure their strength. Only from the other living creatures 

 which surrounded them could they obtain all that was necessary 

 for the maintenance of life, and only by a constant struggle 

 could they wrest these necessities from their rivals and at the 

 same time defend their own lives. So long as man imagined 

 a Creator under human form he supposed the gods to be the 

 creators of all living things — of plants or animals just as we 

 see them around us, of germs destined to evolve according to 

 the process which could be observed every day in the 

 germination of seeds and the hatching of eggs. No further 

 explanation was required. As time went on it was thought that 

 natural forces were in themselves capable of causing 

 germination, or even that certain substances in the course of 

 fermentation, under the action of the sun's rays, either in the 

 secret depths of the ocean or in the bosom of the earth — so 

 often regarded as the great mother of all being — were capable 

 of forming themselves into organisms. To this, the doctrine of 

 spontaneous generation, Joly, Archimede, Pouchet and Musset 

 attempted to give scientific form. It was the doctrine that 

 Aristotle had already advanced ; it had been accepted by 

 Lamarck ; defended against Pasteur by scientists such as 

 Musset, Joly and Pouchet, favoured by the medical men, 

 extolled by the most materialistic philosophers, it finally took 

 on, in the nineteenth century, a quasi-scientific air. 



