62 The Outline of Science 



Various concrete suggestions have been made in regard to 

 the possible origin of living matter, which will be dealt with in a 

 later chapter. So far as we know of what goes on to-day, there 

 is no evidence of spontaneous generation; organisms seem always 

 to arise from pre-existing organisms of the same kind; where any 

 suggestion of the contrary has been fancied, there have been flaws 

 in the experimenting. But it is one thing to accept the verdict 

 "omne vivum e vivo" as a fact to which experiment has not 

 yet discovered an exception and another thing to maintain 

 that this must always have been true or must always remain 

 true. 



If the synthetic chemists should go on surpassing themselves, 

 if substances like white of egg should be made artificially, and if 

 we should get more light on possible steps by which simple 

 living creatures may have arisen from not-living materials, this 

 would not greatly affect our general outlook on life, though it 

 would increase our appreciation of what is often libelled as "inert" 

 matter. If the dust of the earth did naturally give rise very long 

 ago to living creatures, if they are in a real sense born of her and 

 of the sunshine, then the whole world becomes more continuous 

 and more vital, and all the inorganic groaning and travailing 

 becomes more intelligible. 



4 



The First Organisms upon the Earth 



We cannot have more than a speculative picture of the first 

 living creatures upon the earth or, rather, in the waters that 

 covered the earth. A basis for speculation is to be found, how- 

 ever, in the simplest creatures living to-day, such as some of the 

 bacteria and one-celled animalcules, especially those called 

 Protists, which have not taken any very definite step towards 

 becoming either plants or animals. No one can be sure, but there 

 is much to be said for the theory that the first creatures were 



