EVOLUTION TRACED BIOCHEMICALLY 5 I 



to overcome in the evolution of vertebrates, the highest 

 form of life on the globe. In other words, without this 

 control of the composition of the internal medium there 

 would be no vertebrates. 



In conclusion, and to summarize, there were three great 

 epochs in the story of Hfe on the earth. 



The first of these was the generation of hfe itself as 

 an ultramicroscopic organism, the protocyte, as a product 

 after many milhons of syntheses of amino acids, derived 

 from the first constituents of the atmosphere and water 

 of the earth in the beginning of geological time, had achieved 

 the composition of a complex capable of repeating itself by 

 syntheses and thus initiating the long reign of life on the 

 globe. 



The second was the evolution of the cell nucleus as a 

 sanctuary, as it were, to protect the chromatin from the 

 action of the salts of the sea water ever increasing in con- 

 centration and ever invading the cytoplasm of the cell. 

 This protection enabled the chromatin to transmit to 

 offspring cells and organisms inherited characters, and thus 

 to render evolution from stage to stage possible. 



The third was the development of a renal organ which 

 controlled and stabilized the composition of the internal 

 medium, the blood plasma, bathing the cells of vertebrates 

 and thus providing for constancy in the primal concentra- 

 tions of the salts in the cytoplasm of each, inherited from the 

 time, when the cell nucleus was evolved. 



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Allen, F. J. 1899. What is life? Proc. Birminghayn Nat. Hist. & Phil. Soc, 



12: 44-67. 

 Arrhenius, S. 1907. Das Warden der Welten, Trans, from Swedish into 



German by L. Bamberger, Leipzig. English Trans, by H. Borus, 1908. 

 Huxley, T. H. 1870. Pres. Address, Brit. Ass. Adv. Science. Report Brit. 



Assn. 1870, Lond., John Murray. 

 Kelvin, Lord (Sir William Thomson) 1871. Pres. Address, Brit. Ass. Adv. 



Science, Report Brit. Assn. 1871, Lond., John Murray. 

 Macallum, a. B. 1910. The origin of life on the globe. Trans. Can. Inst., 8: 



423-441. 

 Macallum, A. B. 1926. The palaeochemistry of the body fluids and tissues. 



Physiol. Rev., 6: 316. 

 Moore, B. 1912. The Origin and Nature of Life. Home University Library, 



62, Lond., Willams & Norgate. • 



