506 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1912. 



undergone and may still be undergoing to produce living substance. 

 No principle of evolution is better founded than that insisted upon 

 by Sir Charles Lyell, justly termed by Huxley "the greatest geologist 

 of his time," that we must interpret the past history of our globe by 

 the present; that we must seek for an explanation of what has hap- 

 pened by the study of what is happening; that, given similar circum- 

 stances, what has occurred at one time will probably occur at another. 

 The process of evolution is imiversal. The inorganic materials of the 

 globe are continually undergoing transition. New chemical com- 

 binations are constantly being formed and old ones broken up; new 

 elements are making their appearance and old elements disappearing.^ 

 Well may we ask ourselves why the production of Uving matter alone 

 should be subject to other laws than those which have produced, and 

 are producing the various forms of nonhving matter; why what has 

 happened may not happen. If hving matter has been evolved from 

 hfeless in the past, we are justified in accepting the conclusion that 

 its evolution is possible in the present and in the future. Indeed, we 

 are not only justified in accepting this conclusion, we are forced to 

 accept it. When or where such change from nonhving to hving 

 matter may first have occurred, when or where it may have con- 

 tinued, when or where it may still be occurring, are problems as 

 difficult as they are interesting, but we have no right to assume that 

 they are insoluble. 



Since hving matter always contains water as its most abundant 

 constituent, and since the first hving organisms recognizable as such in 

 the geological series were aquatic, it has generally been assumed that 

 life nmst first have made its appearance in the depths of the ocean. ^ 

 Is it, however, certain that the assumption that life originated in the 

 sea is correct ? Is not the land surface of our globe quite as likely to 

 have been the nidus for the evolutionary transformation of nonliving 

 into living material as the waters which surround it? Withm this 

 soil almost any chemical transformation may occur; it is subjected 

 much more than matters dissolved in sea water to those fluctuations 

 of moisture, temperature, electricity, and luminosity wliich are 

 potent in producing chemical changes. But whether life, in the form 

 of a simple shmy colloid, originated in the depths of the sea or on the 

 surface of the land, it would be equally impossible for the geologist 

 to trace its beginnings, and were it still becoming evolved in the same 

 situations, it would be almost as impossible for the microscopist to 

 to follow its evolution. We are therefore not hkely to obtain direct 



1 Soo on the production of elements, W. Crookes, Address to Section B, Brit. Assoc, 1886; T. Preston, 

 Nature, Vol. LX, p. 180; J. J. Thomson, Phil. Mag., 1897, p. 311; Norman Lockyer, op. cit., 1900; G. 

 Darwin, Pres. Addr. Brit. Assoc, 1905. 



« For arguments in favor of the first appearance of life having been in the sea, see A . B. Macallum, " The 

 Paleochemistry of the Ocean," Tians. Canad. lustit., 1903-4. 



