NOTE ON THE PLATES 



Plates III-XXV show the distribution of phosphate and silicate in vertical sections along the lines 

 marked sections 1-17 on the circumpolar chart in Plate I and in the complementary chart in Plate II. 

 The amounts of phosphate and silicate are always expressed as milligrammes P 2 5 or Si0 2 per cubic 

 metre of sea water and are uncorrected for salt error. 



Each of the sections has been drawn projected on to a meridian so that the horizontal distances 

 do not represent actual distances along the sections but only differences of latitude. The latitude 

 and depth scales have been maintained the same throughout so that the sections are comparable; 

 the exaggeration of the vertical scale with respect to the horizontal scale is approximately 370 to 1 . 



The bottom profiles are only schematic. 



The letters AC and STC above the sections mark the positions of the Antarctic and subtropical 

 convergences. 



