526 discovery reports 



Records 14-22 



Dates: 19-24. vi. 26. 



Times : see Fig. n. 



Position: 52° 30' S, 40 46' W to 51' 32' S, 57 36' W. 



Distance: see Fig. 11. 



These records form a series on a line between South Georgia and the Falkland Islands. 

 Records 16 and 21 were faulty, and between records 19 and 20 there is a gap of some 

 50 miles, otherwise they form a continuous series between the positions given. The total 

 distance recorded was 497-4 miles. 



The outstanding feature of these records (Fig. 11) is the marked fluctuation in the 

 numbers of Copepoda. It seems likely that some of these increases must be attributed to 

 vertical migration; thus the concentration between sections 3 and 20 on record 15 and 

 between 7 and 21 on record 17 occurred during periods of night. Record 16 was taken 

 during the day, and although the mechanism jammed and failed to wind on properly, 

 the part of the gauze exposed throughout the run showed that the numbers of Copepoda 

 were small. Records 18, 20 and 22, on the other hand, showed dense concentrations in 

 the daytime and record 19 another at night. Apart from the possible effects of vertical 

 migration the records demonstrate a marked unevenness in the distribution of the 

 copepod population over a wide ocean area. Record 21 (omitted in the figure) could 

 not be estimated quantitatively; owing to a mechanical defect the storage roller was 

 wound so tightly that the plankton was rubbed and pressed into a fine paste. It was 

 evident, however, that throughout the roll there was a thick deposit of Copepoda and 

 young Euphausiacea. Young Euphausiacea were present on all records and showed a 

 marked degree of fluctuation. Adult Euphansia longirostris formed a well-defined patch 

 some 8 miles across on record 22. Chaetognatha were all but absent from records 14- 

 17, but present in small fluctuating numbers on records 18-22. The diatom Rhizosolenia 

 polydactvla formed three patches, one covered by the faulty record 16. 



Record 23 



Dates: 13-14. xi. 26. 



Times: 1500-2030 and 0800-1700. 



Positions: 52 29' S, 9 48' E to 52 37' S, 9 36' E and 53 08' S, 8° 44' E to 53 37' S, 7 45 V E. 



Distances by ship's log: 12-8 and 43-75 miles. 



Record 24 



Dates: 19-20. xi. 26. 

 Times: 1055-2020 and 0800-2100. 



Positions: 53 06' S, i° 29' W to 53 02' S, i' : 56' W and 53 02' S, 2° 25' W to 52° 47' S, 

 2°4i'W. 



Distances by ship's log: 19-7 and 24-5 miles. 



These records are included on account of the dense concentrations of phytoplankton 

 met with and the scarcity of zooplankton. The phytoplankton could not be estimated 

 accurately, but five degrees of density were indicated by a system of + signs. These 



