XII CONTENTS 



ch. 6. Water Sampling and Thermometers by H. F. P. Herdman . 124 



1. Sampling .......... 124 



2. Thermometry ......... 127 



Section II. Fertility of the Oceans . .129 



ch. 7. Productivity, Definition and Measurement by E. Steemann 

 Nielsen .......... 



1. Introduction ........ 



2. Definitions ........ 



3. Methods for measuring primary production . 



4. The relation between the rate of gross production and net 

 production below a surface unit ..... 



5. Transparency of the water versus organic production 



6. The significance of single individual measurements of primary 

 production ........ 



7. The influence of weather conditions .... 



129 

 129 

 133 

 134 



154 

 155 



157 

 159 



ch. 8. Organic Regulation of Phytoplankton Fertility by 

 L. Provasoli ...... 



1. Introduction ..... 



2. Data from chemical analysis 



3. Organic products of algae and bacteria 



4. Nutritional requirements of marine algae 



5. Crustacea and organic solutes 



6. Data from biological analysis of sea -water 



7. Prospects ...... 



8. Addendum ..... 



ch. 9. Bioassay of Trace Substances by W. L. Belsei 



1. Introduction 



2. Vitamins . 



3. Amino acids 



4. Purines and pyrimidines 



5. Perspectives 



165 

 165 

 171 

 175 

 190 

 198 

 198 

 204 

 210 



220 

 220 

 222 



226 

 226 

 227 



COMPARATIVE AND DESCRIPTIVE OCEANOGRAPHY 



Section III. Currents 



235 



ch. 10. Equatorial Current Systems by J. A. Knauss 



1 . Methods of study of ocean currents 



2. Gross circulation pattern 



3. A two-layer ocean — the thermoclinc 



4. Zonal flow — geostrophic currents . 



5. Meridional flow — up welling . 



6. Conclusions and speculations 



235 

 235 

 236 

 239 

 244 

 248 

 250 



