THE LINEAGE OF MAN 



earth's crust, the older sedimentary rocks were soaked and 

 honeycombed with the molten rock coming from below and 

 were squeezed, mashed, folded, contorted, baked, and partly 

 melted, so that if they ever contained any traces of life, such 

 traces would have been hopelessly obliterated, the only pos- 

 sible signs of organic life being the beds of graphite occasion- 

 ally found in the oldest known rock formations. 



Such is the picture suggested to the geologist by the study 

 of the oldest known rocks, now exposed again in eastern 

 Canada, the Lake Superior region, and the Adirondacks as a 

 result of hundreds of millions of years of erosion, but in 

 former ages lying as the "basement complex," beneath tens 

 of thousands of feet of later rocks. 



Passing over various doubtful traces of living organisms in 

 the oldest sedimentary rocks (such as the famous ^'Eozoon 

 canadense," which may be a mineral formation) , we come to 

 certain markings occurring in the Proterozoic limestone for- 

 mations, which were determined by the great palaeontologist 

 C. D. Walcott as the calcareous secretions of algae. In the 

 upper levels of the ''Belt series" of formations in Montana; 

 exposed on the side of a mountain and lying nearly eight 

 thousand feet below the Cambrian, or lower part of the 

 Palaeozoic, Walcott found the fossilized traces of worm bur- 

 rows and trails, seemingly of segmented annelid worms. 



Hence even far below the bottom of the Palaeozoic system, 

 which to the earlier geologists marked the utmost lower 

 limits of the record of fossiP life, we come upon animals of 

 marvelous complexity compared to their one-celled starting 

 point. But where the fossil record fails, the "chain of 

 beings" still in existence apparently preserves some of the 

 main steps in the elaboration of higher living types out of 

 single living cells. For even to-day there are forms of life 

 that afford strong evidence for the following outline. 



[271] 



