364 E. M. KINDLE 



Prof. Benj. Moore discovered that the sea around the Isle of Man was a 

 great deal more alkaline in spring (say April) than it is in summer (say July) ; 

 and then on examining monthly samples taken throughout the year he was able 

 to show that the alkalinity which gets low in summer increases somewhat in 

 autumn, then decreases rapidly during the winter, and after several months of 

 a minimum begins to increase again in March, and rapidly rises to its maximum 

 in April. That is the periodic change of alkalinity and it will be seen to corre- 

 spond roughly with certain very important changes in the living microscopic 

 contents of the sea and the connection between the two may be made out by 

 inquiry into the nature and meaning of the changes in alkalinity. The 



alkalinity of the sea is due to the relative absence of carbon dioxide 



We find that at Port Erin in March the water, not only on the shore, but also 

 out in the open sea, is acid to phenolphthalein, while a month later it is dis- 

 tinctly alkaline to the same indicator and this change signifies an enormous 

 conversion of carbon in the inorganic into carbon in the organic form, a turn- 

 over of such extent that it probably amounts to 20,000 or 30,000 tons of 

 carbon per cubic mile of sea-water Or we may imagine this same quan- 

 tity of carbon as forming the bodies of all the organisms found in the sea all 

 around the shores of the Isle of Man, in which case the 300,000 tons would 

 be distributed through the zone of water extending to about one mile out from, 

 the shore and down to an average depth at that distance of, say, ten fathoms. 

 Now all of these organisms have obtained their carbon from the carbon dioxide 

 present in the sea-water in spring and it is absolutely certain that in the absence 

 of this abundant supply of available carbon-food, the millions and millions 

 or organisms in question could never have existed." .... "Practically all 

 our food-fishes in the sea, except the herring, produce thei^^ eggs in winter or 

 early spring. They are hatching out in vast quantities during the time that 

 the alkalinity is rapidly increasing and the phytoplankton of diatoms is daily 

 growing in amount. "^ 



It is evident that the vast increase in the quantity of marine 

 life during the spring and summer must be registered in sea-bottom 

 deposition by -a corresponding increase in the amount of diatom 

 and other organic materials dropped on the sea bottom. We have 

 therefore throughout the seas of the temperate and northern parts 

 of the earth annually a summer period of maximum sedimentation 

 following a winter period of minimum sedimentation. 



CONCLUSIONS 



The evidence appears to be distinctly against uniformity in 

 sedimentation. Biologists in recent years have generally accepted 



' W. A. Herdman, "Some Periodic Changes in Nature," 32d Ann. Kept. Liverpool 

 Marine Biology Committee (1918), pp. 23, 24, and 27. 



I 



