34 THE ORIGIN AND EVOLUTION OF LIFE 



what it is at present; and thus the present chemical composi- 

 tion of terrestrial matter, of the sea, and of the air, as indi- 

 cated by Table I, is by no means the same as its primordial 

 composition 80.000,000 years ago. 



In Table I all the chemical "life elements" which enter 

 more or less freely into organic compounds are indicated by 

 italics, shoiving that life has taken up and ?nade use of practically 

 all the chemical elements of frequent occurrence in the rocks, 

 waters, and air, with the exception of aluminum, barium, and 

 strontium, which are extremely rare in life compounds, and 

 of titanium, which thus far has not been found in any. But 

 even these elements appear in artificial organic compounds, 

 showing combining capacity without biological "inclination" 

 thereto. In the life compounds, as in the lithosphere and 

 hydrosphere, it is noteworthy that the elements of least atomic 

 weight (Table II) predominate over the heavier elements. 



Primordial Environment — The Lifeless Water 



According to the nebular theory of Laplace the waters 

 originated in the primordial atmosphere; according to the 

 planetesimal theory of Chamberlin^ and Moulton,- the greater 

 volume of water has been gradually added from the interior 

 of the earth through the vaporous discharges of hot springs. 

 As Suess observes: "The body of the earth has given forth its 

 ocean." 



From the beginning of Archaeozoic time, namely, back to a 

 period of 80,000,000 years, we have little biologic or geologic 

 evidence as to the stability of the earth. From the beginning 

 of the Palaeozoic, namely, for the period of the last 30,000,000 

 years, the earth has been in a condition of such stability that 



1 Chamberlin, Thomas Chrowder, 1916. - Moulton, F. R., 191 2, p. 244. 



