PHYTOPLANKTON OF SOUTH GEORGIA 



45 



show a progressive increase. At the four outer stations on the hne these small forms 

 were dominant with the single exception of St. 477, where Ch. criophilum was the 

 most numerous diatom. This may be taken as almost conclusive evidence of the 

 presence of old Bellingshausen Sea water. The nature of the phytoplankton taken on the 

 Bird Island line thus affords good evidence of mixing of the two types of surface water 

 to the north of South Georgia at this time, while farther out to the north-west old 

 Bellingshausen Sea water was to be found. 



Table 7 



The next line of stations to be described was worked roughly south-westwards from 

 Annenkov Island (Fig. 4) ; actually it was the last hne worked on this survey, but as the 

 whole survey was accomplished in a very short space of time, and the phytoplankton 

 lends itself to natural explanation in this sequence, the order in which the lines are 

 described seems well justified. 



The full analyses of the hauls taken on the Annenkov Island Hne are shown in 

 Table XII. From this it will at once be seen that the hauls were extremely heavy, with 

 a vast profusion of small forms. The value of the percentages, which could only be 

 calculated apart from the forms which defied estimation, is thus vitiated. Nevertheless, 

 Table 8 gives some idea of the main features of the phytoplankton taken on this line. 



The hauls obtained here show such a marked difference from those taken to the north 

 and north-east of the island during this survey that it is probable that we have to deal 

 with an entirely different type of surface water. As far as one can judge from the 

 character of the phytoplankton alone this is indeed the case, the dominant species here 

 pointing to the western Weddell Sea origin of the bulk of the water, especially in- 

 shore, with a certain amount of mixing with old Bellingshausen Sea water, more 

 particularly at the middle and outer end of the line. 



