EVIDENCES OF PRIMITIVE LIFE WALCOTT. 243 



THE SEARCH AMONG THE ROCKS OF CAMBRIAN TIME, AND EARLY 

 INCENTIVE TO dO TO THE ROCKY MOUNTAINS. 



Friends have often asked how I happened to take up geologic work 

 in the Eocky Mountains. The reason is a very simple one. As a boy 

 of 17 I planned to study those older fossiliferous rocks of the North 

 American Continent which the great English geologist, Adam Sedg- 

 wick, had called the Cambrian system on account of his finding them 

 in the Cambrian district of Wales.^ 



The early explorers of the Rocky Mountains and large plateaus 

 Avrote of great masses of ancient bedded rocks exposed by mountain 

 uplifts and deep canyons, and so I have taken advantage of every 

 opportunity to visit and work in that great wonderland. This study 

 has led me to many wild and beautiful regions, where nature has 

 glorified these old sea beds by thrusting them up into mountain 

 masses, with forests below and crowns of perpetual snow and ice on 

 their summits. 



From the vicinity of our Burgess Pass camp in the Canadian 

 Rockies the views were most beautiful and varied, changing from 

 hour to hour during the day and from day to day with the varying 

 atmospheric conditions. Emerald Glacier was most attractive in the 

 bright sunlight, in the gray light of early morning, the shadows of 

 sunset, or when snow and fog were sweeping over the range, giving 

 only now and then a glimpse of the ice and cliffs. The light-colored 

 moraines on either side of its foot and the dark rocks afforded a 

 beautiful setting for the ice, and across the Yoho Pass the cliff of 

 Mount Wapta stood in bold relief, with a steep slope of broken rock 

 on the west, and a huge bank of snow on the eastern side of its south 

 ridge. 



Our camp at Lake O'Hara (7,000 feet) (pi. 6) was in a beautiful 

 mountain meadow at the foot of Mount Schaffer, where the morning 

 and evening views of the surrounding mountains were often superb. 

 Snow squalls are not infrequent on the higher summits, and on July 

 17 snow fell at the camp nearly all day. As seen from a slope of 

 Mount Odaray, Lake O'Hara rests like an emerald in a bowl of 

 mountains, reflecting the glaciers of Mounts Lef roy and Hungabee. 



CAMBRIAN SECTIONS. 



My first study of a great section of Paleozoic rocks of the western 

 side of North America was that of the Eureka mining district of 

 Nevada.^ This was followed by the section of the Grand Canyon of 



1 Cambria (or Cymru) was the ancient name for Wales. 



2 Monograpli 8, U. S. t>ol. Survey, 1884. 



