108 life's beginning on the earth 



First: the relative amount of the several salts is not ex- 

 actly alike, although there is a preponderance of sodium 

 chloride in both. 



Second: the total salt content of the blood is only about 

 0.9 per cent; in the ocean, however, if is 3.5 per cent. 



The last deviation is not at all surprising ; on the contrary 

 it seems to corroborate our assumption. For, our blood is 

 certainly not derived from the modern ocean but from the 

 ancient ocean that existed hundreds of millions of years ago, 

 when our ancestors left it to adapt themselves to life on the 

 land. We have to consider that the salt which is now dis- 

 solved in the ocean has been extracted from the surface 

 layers of the earth by rivers. This process of extraction 

 still goes forward. In the remote past, the salt concentra- 

 tion of the ocean must have been appreciably lower. It 

 was then that the first animals left the ocean and adapted 

 themselves to conditions on land. They have preserved 

 the low salt concentration of the early ocean, in which, 

 probably, the relative amount of the salts differed from that 

 in the modern ocean. Furthermore, the surface of the 

 earth, and hence the ocean, was then probably warmer than 

 it is now. The warm blood of the body may be looked upon 

 as another inheritance which has been kept at an even level, 

 reminding us of the oceanic existence of our very remote 

 aquatic forebears. 



It seems therefore that even man, "the crown of evolu- 

 tion," carries within himself a small part of that original 

 ocean, low in salt content and of a higher temperature, as 

 it was at the time of man's earliest ancestors. Times have 

 certainly changed a great deal since then, yet the old ocean 

 still persists in us. Its salt concentration and temperature 

 is constantly kept at the same level by the regulating action 

 of our internal organs, particularly by the kidneys. Not 

 only is the total content thus kept constant but also the 

 concentration of each of the several sails of (he ancient ocean. 



