DISCOVERY REPORTS 



silicate analysis. The silicate results are given according to the standards of King and 

 Lucas (1928). 



I should like to express my indebtedness to my colleagues, Mr H. F. P. Herdman and 

 Dr G. E. R. Deacon, who have assisted me in collecting all the samples and, together 

 with Mr Saunders, have helped to make the estimations on which this report is founded. 

 In the actual writing of the report I have been very fortunate in having access to a proof- 

 copy of Dr Deacon's "Hydrology of the Southern Ocean", Discovery Reports, xv, 



120° 



BOW 



/ 

 156 

 w [^ 



ISO 



w 



n 1 



35"S 



Fig. 1. Positions of stations where observations for phosphate or silicate were made in the South Pacific 



sector of the Southern Ocean. 



pp. 1-124, which has been of great help. Dr T. J. Hart and I have discussed many of 

 the problems which have arisen, and I am indebted to him for many suggestions and 

 for all my facts about phytoplankton. Finally, but by no means least, the samples could 

 only have been obtained by the full co-operation and skill of the ship's officers and by 

 the loyal and painstaking service of the seamen, often in the worst of weathers. 



Figs. 1-5 show the position of the majority of the stations at which observations were 

 made. In some of the routine lines of repeated observations and in particular in the 

 Scotia Sea and in 8o° W, all the stations are not shown. 



Before proceeding to the main portion of this report a preliminary and very brief 

 account of the chief water layers of the Southern Ocean and their movements will be 



