168 THE FITNESS OF THE ENVIRONMENT 



tion of ionized hydrogen is from 0.00000001 IN 

 to 0.0000000045 N. In his studies during a 

 voyage of five months in the summer season 

 of 1910 of the Danish steamship Thor, Palitzsch 

 made the following observations : * surface 

 water from the Skager-Rack, from the south- 

 ern portions of the North Sea, and from the 

 west of the Baltic ranged from about 

 0.000000010 N to about 0.000000009 N ; in the 

 North Sea the surface water varied from 

 0.0000000083 N to 0.0000000074 N; at the lati- 

 tude of Murray Firth, twenty miles from the 

 coast, the values were between 0.0000000071 N 

 and 0.0000000066 N. In the Atlantic the 

 surface water corresponded in the most north- 

 ern portions to that of the North Sea, while in 

 the Bay of Biscay and along the coast of 

 Portugal the values were 0.0000000056 N, 

 corresponding to slightly increased alkalinity, 

 especially if account be taken of the rising 

 temperature. In general the waters of the 

 Mediterranean corresponded to those of the 

 coast of Portugal. But from the Sea of Mar- 

 mora, the Bosphorus, and the Black Sea 

 samples were obtained which gave the value 

 0.0000000045 N. 



In general, as the depth increased, the 



1 Palitzsch, " Comptes-rendus des travaux du Laboratoire 

 de Carlsberg," lOme Volume, p. 85, 1911. 



