NO. 12 CHARLES DOOLITTLE WALCOTT 7 



having a picture of the kind of thing that it would be important to 

 find and of the place where if found, it would be especially significant. 



This is not the time or place to discuss in detail the contributions 

 Doctor Walcott made to the study of the early life of the earth, as to 

 the structure of ancient animals, their biological classification, their 

 faunal grouping, or their succession in time. It is, however, important 

 to note that in all of these aspects of the problem his accomplishments 

 belong in the first rank of the world's researches. In studies ranging 

 from a fundamental investigation of structure and habits of many 

 groups of trilobites and other crustaceans, of the niollusca and the 

 mollusk-like brachiopods, the early coral-like forms, the simple pro- 

 tozoa, and the bacteria, his work was of the pathfinding type. 



In the whole range of researches of the world Doctor Walcott's 

 studies of the earliest known assemblages of life, and his working 

 out of the facts relating to the earliest traces of life upon the earth, 

 constitutes the most important single contribution. It marks his 

 greatest achievement in contribution to knowledge and to constructive 

 or interpretative thought. 



In his work on the " Origin of Species," Charles Darwin gave large 

 value to certain evidence against his theory of evolution which is 

 presented by the earlier part of the geological record of life. With 

 that perfectly balanced judgment which characterized his work, Dar- 

 win discussed the fact that a full representation of highly developed 

 and widely dififerentiated life beginning in the formations known as 

 the Cambrian at the bottom of the geological column, did not give 

 the picture of beginnings of life that his theory of evolution seemed 

 to require. Darwin considered (to quote his words) that " The diffi- 

 culty of assigning any good reason for the absence of vast piles of 



strata rich in fossils beneath the Cambrian is very great 



The case at present must remain inexplicable, and may be truly urged 

 as a valid argument against the views here entertained." He believed, 

 however, that many existing factors opened the way for satisfactory 

 interpretation of the situation and that it would (to quote him) " be 

 about as rash to dogmatize on the succession of organic forms as it 

 would be for a naturalist to land for five minutes on a barren point 

 in Australia, and then to discuss the number and range of its 

 productions." 



It was this field which Darwin considered so difficult and so 

 important, extending from the better understood ancient or " Pale- 

 ozoic " rocks through to the lowest known strata, in which Doctor 

 Walcott planned his attack and made his outstanding contribution. 

 His full description and interpretation of the earliest faunas, and his 



