50 EVOLUTION 



When did the first living things first appear on this 

 planet ? Where did they come from ? What was their 

 character? These three questions naturally occur to 

 one as of the greatest interest at the commencement of 

 the story of organic evolution, and some attempt must 

 be made at least to define the limits of our knowledge 

 on the matter. Let us say at once that our knowledge 

 is very limited indeed. We have not the smallest shred 

 of direct information in regard to any one of these 

 questions. For the later chapters in the story of 

 organic evolution, we have a rich supply of documents 

 in the fossilised remains of animals and plants that have 

 been cut out of the rocks and stored in our museums. 

 But a glance at any well-arranged collection of fossils 

 shows at once the limitation of this information. It 

 does not bring us anywhere near the real beginning of 

 the story. The first fossil remains of plants are 

 impressions of large and complex seaweeds in the 

 Cambrian strata : the first animal remains are petrified 

 Crustacea and traces of worms. These imply that the 

 story of life had already run through whole volumes, 

 during millions of years, and of these earlier volumes 

 we have only charred masses of carbon, lime, and iron 

 the ashes, as it were, from the burning of those interest- 

 ing early volumes. Of the very earliest we have no 

 trace whatever. 



The prevailing and proper attitude of the scientific 

 man when confronted with our three questions is, 

 therefore, one either of silence or of conjecture. He 

 generally assumes, on good scientific ground, that the 

 earliest living things appeared in the warm primitive 

 ocean during what is called the Archaean period, 

 because they are found to be already much advanced 

 in organisation In the Cambrian strata. He further 

 assumes that they were of an even simpler type than 



