72 



DISCOVERY REPORTS 



St. WS 61 and St. 151 lie farther out from the general region of the survey. Their 

 phytoplankton is similar in type to Group 3, but the former has in addition a fair 

 quantity of Chaetoceros schimperianus and the latter a large quantity of Rhizosolenia 

 styliformis. As St. 151 is near the mixing of Weddell and Bellingshausen Sea waters, the 

 Rhizosolenia, which is characteristic of Group 1, may have a Bellingshausen Sea origin, 

 although it was present in moderate numbers in the Weddell Sea water of Group 4. 



Phytoplankton Group 5. This group includes four stations, 130, 134, WS 41 and 

 WS 42, with very little phytoplankton in the region of coastal water of low salinity. See 

 Appendix I. 



•J' 



H^H& 



•j 



•D 



D 





•D -D -D 



D= Period December is -23 

 J = Period January 7-10 

 J'= Period January i6-ao 



Fig. 37. Chart showing the time distribution of stations in the South Georgia plankton survey of December- 

 January 1926-7. 



One matter we must bear in mind when considering the results of the survey is that 

 all the stations were not taken at the same time. They fall into two main separate periods 

 as shown in Fig. 37. Those on the western side of the island were taken three weeks later 

 than those on the eastern side — and the three outlying stations a week later again. We 

 know what changes can take place in even so short a time. The C line in November 

 (26th to 30th) was massed with Thalassiosira antarctica; yet on the same line in De- 

 cember (20th and 2 1 st) there was not a single specimen of this diatom to be seen. The 



